阅读说明：本技术 印刷预处理液、印刷用基材及图像记录方法 (Printing pretreatment liquid, printing base material, and image recording method ) 是由 深川清隆 杉岛明典 藤井勇介 于 2018-12-21 设计创作，主要内容包括：本发明提供一种包含Hansen溶解度参数的值为18MPa<Sup>0.5</Sup>以上且30MPa<Sup>0.5</Sup>以下的聚合物、水、选自包括多价金属盐、有机酸、阳离子性化合物及金属络合物的组中的至少1种凝聚剂的聚酯基材用印刷预处理液以及其应用。(The invention provides a compound containing Hansen solubility parameter with the value of 18MPa 0.5 Above and 30MPa 0.5 The printing pretreatment liquid for polyester substrates comprises a polymer, water, and at least 1 coagulant selected from the group consisting of polyvalent metal salts, organic acids, cationic compounds, and metal complexes.)

1. A printing pretreatment liquid for polyester substrates, which comprises a Hansen solubility parameter of 18MPa^0.5Above and 30MPa^0.5The water-soluble polymer composition comprises the following polymer, water, and at least 1 flocculant selected from the group consisting of polyvalent metal salts, organic acids, cationic compounds, and metal complexes.

2. The printing pretreatment liquid according to claim 1,

the value of the Hansen solubility parameter is 18MPa^0.5Above and 30MPa^0.5The following polymers comprise a polymer selected from the group consisting of polymers having SO₃ ^-Z⁺Polyester resin of group having SO₃ ^-Z⁺Based polyamide resin having SO₃ ^-Z⁺(meth) acrylic resin of radical and having SO₃ ^-Z⁺At least 1 of the polyesteramide copolymers of (A) and (B),

SO₃ ^-Z⁺in the basic formula, Z⁺Is represented by formula (I) and SO₃ ^-Bonded or dissociated counter cations.

3. The printing pretreatment liquid according to claim 1 or 2,

the value of the Hansen solubility parameter is 18MPa^0.5Above and 30MPa^0.5The following polymer contains at least one of a resin having a constituent unit represented by the following formula (I) and a resin having a constituent unit represented by the following formula (II),

in the formula (I), Z⁺Is represented by formula (I) and SO₃ ^-A counter cation which is bonded or dissociated,

in the formula (II), R¹Represents a hydrogen atom or a methyl group, R²Represents a single bond, an aromatic ring, or an alkylene group which may contain an ester bond, an amide bond, or an oxygen atom, Z⁺Is represented by formula (I) and SO₃ ^-Bonded or dissociated counter cations.

4. The printing pretreatment liquid according to claim 3,

the resin having a constituent unit represented by formula (I) further has a constituent unit represented by formula (I),

5. the printing pretreatment liquid according to claim 3,

the resin having a constituent unit represented by the formula (II) further has a constituent unit represented by the following formula (III),

in the formula (III), R³Represents a hydrogen atom or a methyl group, R⁴And R⁵Each independently represents a hydrogen atomOr alkyl which may contain oxygen atoms, R⁴And R⁵May be bonded to form a ring containing an oxygen atom.

6. The printing pretreatment liquid according to claim 3 or 5,

the resin having the constituent unit represented by formula (II) further has a constituent unit derived from styrene.

7. The printing pretreatment liquid according to claim 3, 5 or 6,

the resin having the constituent unit represented by formula (II) further has an alkyl (meth) acrylate having no sulfonic acid group.

8. The printing pretreatment liquid according to any one of claims 1 to 7,

the value of the Hansen solubility parameter is 18MPa^0.5Above and 30MPa^0.5The glass transition temperature Tg of the polymer is 40 ℃ to 200 ℃.

9. The printing pretreatment liquid according to any one of claims 1 to 8,

at least 1 coagulant selected from the group consisting of polyvalent metal salts, organic acids, cationic compounds and metal complexes, having a Hansen solubility parameter of 25MPa^0.5Above 40MPa^0.5The following.

10. The printing pretreatment liquid according to any one of claims 1 to 9,

the value of the Hansen solubility parameter is 18MPa^0.5Above and 30MPa^0.5The mass ratio of the content A of the polymer to the content B of at least 1 flocculant selected from the group consisting of polyvalent metal salts, organic acids, cationic compounds and metal complexes is the content A of the polymer to the content B of the flocculant is 10:1 to 1:2.

11. A printing substrate comprising:

a polyester substrate; and

a treatment layer comprising a solid component of the printing pretreatment liquid described in any one of claims 1 to 10 disposed on a surface of a polyester substrate.

12. A method for producing a printing substrate, comprising the step of applying the printing pretreatment liquid according to any one of claims 1 to 10 to the surface of a polyester substrate.

13. An ink set comprising: an ink composition comprising a colorant and water, and the printing pretreatment liquid of any one of claim 1 to claim 10.

14. An image recording method, comprising:

a step of applying the printing pretreatment liquid according to any one of claims 1 to 10 to a surface of a polyester substrate; and

and a step of recording an image by discharging an ink composition containing a colorant and water by an ink jet method on the surface to which the printing pretreatment liquid is applied.

15. An image recording method comprising a step of recording an image by discharging an ink composition containing a colorant and water by an ink jet method onto a treatment layer of a printing substrate comprising a polyester substrate and a treatment layer containing a solid component of the printing pretreatment liquid according to any one of claims 1 to 10 provided on a surface of the polyester substrate.

16. An image recorded matter having a polyester substrate and an image comprising a solid component of the printing pretreatment liquid as claimed in any one of claim 1 to claim 10 and a colorant provided on a surface of the polyester substrate.

Technical Field

The present invention relates to a printing pretreatment liquid, a printing substrate, a method for producing a printing substrate, an ink set, an image recording method, and an image recorded matter.

Background

Recording methods using the ink jet method are widely used for recording high-quality images on various substrates by ejecting ink in the form of droplets from a plurality of nozzles provided in an ink jet head.

Various image recording methods using the ink jet method have been proposed.

For example, a method of using an ink set in which an ink containing water and a colorant and a pre-treatment liquid for printing containing a coagulant for coagulating components in the ink are used together is known. In this method, by bringing the ink into contact with the printing pretreatment liquid, for example, an image excellent in resolution can be formed.

For example, japanese patent application laid-open No. 2017-013350 discloses a recording method including: a first drying step (1) of applying the pretreatment liquid to the recording medium and drying the recording medium at a drying temperature T1; a second drying step of applying the ink composition to the recording medium coated with the pretreatment liquid and drying the recording medium at a drying temperature T2; and a 3 rd drying step of applying a post-treatment liquid to the recording medium to which the ink composition is adhered and drying the recording medium at a drying temperature T3, wherein the pre-treatment liquid contains a resin having a glass transition temperature Tg1, the ink composition contains a resin having a glass transition temperature Tg2, and the post-treatment liquid contains a resin having a glass transition temperature Tg3, and satisfies the relationships of (1) Tg1 < Tg2 < Tg3 and (2) T1 < T2 < T3.

Further, japanese patent application laid-open No. 2016-.

Disclosure of Invention

Technical problem to be solved by the invention

The polyethylene base material is a recording medium that is not easily penetrated by ink containing a colorant and water.

As a result of intensive studies, the present inventors have found that an insufficient adhesion of an image to a polyester substrate is obtained by applying a treatment liquid or the like to the polyester substrate and recording an image based on an ink containing a colorant and water using the techniques described in japanese patent application laid-open nos. 2017-013350 and 2016-030337.

Accordingly, an object to be solved by the embodiments of the present invention is to provide a pretreatment liquid for printing that improves the adhesion between a polyester substrate and an image formed with an ink containing a colorant and water.

Another object of another embodiment of the present invention is to provide a printing substrate, a method for producing a printing substrate, and an image recorded matter, each of which has excellent adhesion of an image formed using an ink containing a colorant and water.

Further, another object of the present invention is to provide an ink set and an image recording method for forming an image based on an ink containing a colorant and water, which have excellent adhesion to a polyester substrate.

Means for solving the technical problem

Specific means for solving the problems include the following means.

< 1 > a printing pretreatment liquid for polyester substrates comprising a value of Hansen (Hansen) solubility parameter of 18MPa^0.5Above and 30MPa^0.5The water-soluble polymer composition comprises a polymer, water, and at least 1 flocculant selected from the group consisting of polyvalent metal salts, organic acids, cationic compounds, and metal complexes.

< 2 > the printing pretreatment liquid according to < 1 > wherein,

the value of the Hansen solubility parameter is 18MPa^0.5Above and 30MPa^0.5The following polymers comprise a polymer selected from the group consisting of polymers having SO₃ ^-Z⁺Polyester resin of group having SO₃ ^-Z⁺Based polyamide resin having SO₃ ^-Z⁺(meth) acrylic resin of radical and having SO₃ ^-Z⁺At least 1 of the polyesteramide copolymers.

SO₃ ^-Z⁺In the basic formula, Z⁺Is represented by formula (I) and SO₃ ^-Bonded or dissociated counter cations.

< 3 > the printing pretreatment liquid according to < 1 > or < 2 >, wherein,

the value of the Hansen solubility parameter is 18MPa^0.5Above and 30MPa^0.5The following polymer includes a resin having a constituent unit represented by the following formula (I) and a resin having a constituent unit represented by the following formula (II)At least one of the fats is selected from the group consisting of,

[ chemical formula 1]

In the formula (I), Z⁺Is represented by formula (I) and SO₃ ^-Bonded or dissociated counter cations.

In the formula (II), R¹Represents a hydrogen atom or a methyl group, R²Represents a single bond, an aromatic ring, or an alkylene group which may contain an ester bond, an amide bond, or an oxygen atom, Z⁺Is represented by formula (I) and SO₃ ^-Bonded or dissociated counter cations.

< 4 > the printing pretreatment liquid according to < 3 > wherein,

the resin having a constituent unit represented by formula (I) further has a constituent unit represented by formula (I) below.

[ chemical formula 2]

< 5 > the printing pretreatment liquid according to < 3 >, wherein,

the resin having the structural unit represented by the formula (II) further has a structural unit represented by the following formula (III).

[ chemical formula 3]

In the formula (III), R³Represents a hydrogen atom or a methyl group, R⁴And R⁵Each independently represents a hydrogen atom or an alkyl group which may contain an oxygen atom, R⁴And R⁵May be bonded to form a ring containing an oxygen atom.

< 6 > the printing pretreatment liquid according to < 3 > or < 5 >, wherein,

the resin having the constituent unit represented by formula (II) further has a constituent unit derived from styrene.

< 7 > the printing pretreatment liquid according to < 3 >, < 5 >, or < 6 >, wherein,

the resin having the constituent unit represented by formula (II) further has an alkyl (meth) acrylate having no sulfonic acid group.

< 8 > the printing pretreatment liquid according to any one of < 1 > to < 7 >, wherein,

the value of the Hansen solubility parameter is 18MPa^0.5Above and 30MPa^0.5The glass transition temperature Tg of the polymer is 40 ℃ to 200 ℃.

< 9 > the printing pretreatment liquid according to any one of < 1 > to < 8 >, wherein,

at least 1 coagulant selected from the group consisting of polyvalent metal salts, organic acids, cationic compounds and metal complexes, having a Hansen solubility parameter of 25MPa^0.5Above 40MPa^0.5The following.

< 10 > the printing pretreatment liquid according to any one of < 1 > to < 9 >, wherein,

the value of the Hansen solubility parameter is 18MPa^0.5Above and 30MPa^0.5The mass ratio of the content A of the polymer to the content B of at least 1 flocculant selected from the group consisting of polyvalent metal salts, organic acids, cationic compounds and metal complexes is 10:1 to 1:2.

< 11 > a printing substrate having:

a polyester substrate; and

a treatment layer disposed on a surface of the polyester substrate and containing a solid component of the printing pretreatment liquid of any one of < 1 > to < 10 >.

< 12 > a method for producing a printing substrate, which comprises a step of applying the printing pretreatment liquid described in any one of < 1 > to < 10 > to the surface of a polyester substrate.

< 13 > an ink set comprising an ink composition comprising a colorant and water, and the printing pretreatment liquid of any one of < 1 > to < 10 >.

< 14 > an image recording method having:

a step of applying the printing pretreatment liquid described in any one of < 1 > to < 10 > to the surface of a polyester substrate; and

and a step of recording an image by discharging an ink composition containing a colorant and water by an ink jet method on the surface to which the printing pretreatment liquid is applied.

< 15 > an image recording method comprising a step of recording an image by discharging an ink composition containing a colorant and water by an ink jet method on a treatment layer of a printing substrate comprising a polyester substrate and, provided on a surface of the polyester substrate, a treatment layer containing a solid content of the printing pretreatment liquid described in any one of < 1 > to < 10 >.

< 16 > an image recorded matter having a polyester substrate and an image comprising a solid component of the printing pretreatment liquid and a colorant as set forth in any one of < 1 > to < 10 > disposed on a surface of the polyester substrate.

Effects of the invention

According to the embodiment of the present invention, a printing pretreatment liquid capable of improving the adhesion between a polyester substrate and an image formed by an ink containing a colorant and water can be provided.

Further, according to another embodiment of the present invention, a printing substrate, a method for producing a printing substrate, and an image recorded matter, which are excellent in adhesion of an image based on an ink containing a colorant and water, can be provided.

Further, according to another embodiment of the present invention, an ink set and an image recording method for forming an image based on an ink containing a colorant and water, which have excellent adhesion to a polyester substrate, can be provided.

Drawings

Fig. 1 is a schematic configuration diagram showing a configuration example of an image recording apparatus used in the implementation of an image recording method.

Fig. 2 is a diagram conceptually showing characters in a character image used for evaluation of image resolution in the embodiment.

Fig. 3 is a diagram for explaining details of evaluation criteria of image resolution in the embodiment.

Detailed Description

In the present invention, the numerical range represented by "to" means a range in which the numerical values recited before and after "to" are included as the lower limit value and the upper limit value. In the numerical ranges recited in the present invention, the upper limit or the lower limit recited in one numerical range may be replaced with the upper limit or the lower limit recited in another numerical range recited in a stepwise manner. In the numerical ranges described in the present invention, the upper limit or the lower limit described in a certain numerical range may be replaced with the values shown in the examples.

In the present invention, the amount of each component in the composition refers to the total amount of a plurality of substances present in the composition, when the plurality of substances corresponding to each component are present in the composition, unless otherwise specified.

In the present invention, the term "step" is included in the term not only in an independent step but also in a case where the step cannot be clearly distinguished from other steps as long as the intended purpose of the step is achieved.

In the present invention, "printing" means drawing an image such as a character or a pattern with an ink, and "image recording" or "recording of an image" means drawing an image on a polyester substrate using a printing pretreatment liquid (or a treatment layer containing a solid component of the printing pretreatment liquid) and an ink and fixing the drawn image.

In the present invention, the solid content means the remaining part of the printing pretreatment liquid from which the solvent such as water and organic solvent is removed, and the amount of the solid content means the mass of the remaining part of the printing pretreatment liquid from which the solvent such as water and organic solvent is removed.

In the present invention, inkjet printing is preferable as a printing method.

In the present invention, "(meth) acrylic acid" means at least one of acrylic acid and methacrylic acid, and "(meth) acrylate" means at least one of acrylate and methacrylate.

In the present invention, a combination of preferred embodiments is a more preferred embodiment.

< pretreatment liquid for printing >

The printing pretreatment liquid comprises a Hansen solubility parameter and has a value of 18MPa^0.5Above and 30MPa^0.5A printing pretreatment liquid for polyester substrates, which comprises the following polymer, water, and at least 1 flocculant selected from the group consisting of polyvalent metal salts, organic acids, cationic compounds, and metal complexes.

Hereinafter, the value of the Hansen solubility parameter is also referred to as "HSP value", and the value of the Hansen solubility parameter is 18MPa^0.5Above and 30MPa^0.5The following polymers are also referred to as "specific polymers".

As a result of studies on the polymer contained in the printing pretreatment liquid, the present inventors found that physical property values such as HSP value are in a specific range (i.e., 18 MPa)^0.5Above and 30MPa^0.5Below), the adhesion between the polyester substrate and the image formed by the ink containing the colorant and water is improved.

Further, since the pre-treatment liquid for printing according to the present invention contains a coagulant, it is possible to form an image having excellent image quality by using the pre-treatment liquid for printing according to the present invention.

Hereinafter, each component contained in the printing pretreatment liquid according to the present invention will be described in detail.

[ specific Polymer ]

By specific polymer is meant a HSP value of 18MPa^0.5Above and 30MPa^0.5The following polymers.

The use of the specific polymer according to the present invention enables the adhesion of a polyester substrate to an image formed from an ink containing a colorant and water to be improved.

The specific polymer is not particularly limited as long as the HSP value is within the above range.

From the viewpoint of further improving the above-mentioned adhesiveness, the HSP value of the specific polymer is preferably 20MPa^0.5Above and 26MPa^0.5Hereinafter, more preferably 21MPa^0.5Above and 24MPa^0.5The following.

The mode of printing the specific polymer in the pretreatment liquid is not particularly limited, and may be a mode of particles, or a mode of dissolving in water, a solvent, or the like.

Examples of the specific polymer include polyester resins, polyamide resins, (meth) acrylic resins, styrene resins, vinyl resins, polyolefin resins, polyurethane resins, polycarbonate resins, polydiene resins, epoxy resins, silicone resins, cellulose resins, chitosan resins, and copolymers comprising a combination of constituent units of these resins.

The specific polymer is preferably at least 1 selected from the group consisting of polyester resins, polyamide resins, (meth) acrylic resins, and copolymers comprising a combination of constituent units of these resins.

(specific Polymer having sulfonic acid group)

From the viewpoint of further improving the adhesion between the polyester substrate and an image formed by an ink containing a colorant and water, and from the viewpoint of excellent liquid storage stability of the prepared printing pretreatment liquid, and the like, a specific polymer having a sulfonic acid group is preferable as the specific polymer.

As the specific polymer having a sulfonic acid group, at least 1 selected from the group consisting of a polyester resin having a sulfonic acid group, a polyamide resin having a sulfonic acid group, a (meth) acrylic resin having a sulfonic acid group, and a copolymer having a sulfonic acid group in which constituent units of these resins are combined is preferable.

The "copolymer having sulfonic acid groups and obtained by combining constituent units of these resins" is preferably a polyesteramide copolymer having sulfonic acid groups.

Among them, from the viewpoint of further improving the adhesion of the polyester substrate to an image formed by an ink containing a colorant and water, the specific polymer is preferably at least 1 selected from the group consisting of a polyester resin having a sulfonic acid group (hereinafter, also referred to as "specific polymer 1"), a polyesteramide copolymer having a sulfonic acid group (hereinafter, also referred to as "specific polymer 2"), and a (meth) acrylic resin having a sulfonic acid group (hereinafter, also referred to as "specific polymer 3").

Here, the sulfonic acid group as the specific polymer is represented by SO₃ ^-Z⁺In the printing pretreatment liquid, SO₃ ^-Z⁺Z of radical⁺Is represented by formula (I) and SO₃ ^-Bonded or dissociated counter cations.

In the present invention, the (meth) acrylic resin means a resin containing at least 1 or more kinds of constituent units derived from a (meth) acrylate ester.

Polyester resin having sulfonic acid group (specific Polymer 1) -

The polyester resin having a sulfonic acid group (specific polymer 1) may be a resin synthesized by using a resin having a sulfonic acid group in at least one of a polycarboxylic acid compound, an alkyl ester thereof, and a polyol compound, or a resin obtained by introducing a sulfonic acid group into a synthesized polyester resin (for example, a polyester resin having no sulfonic acid group).

Examples of the polycarboxylic acid compound having a sulfonic acid group or its alkyl ester used for synthesizing the specific polymer 1 include sodium dimethyl 5-sulfoisophthalate and sodium 2-sulfoterephthalate, and among these, sodium dimethyl 5-sulfoisophthalate is preferably used from the viewpoint of the ease of the method for synthesizing the polymer.

On the other hand, examples of the polyol compound having a sulfonic acid group include sodium phenyl 1, 4-dihydroxy-2-sulfonate, sodium phenyl 1, 3-dihydroxymethyl-5-sulfonate, sodium 2-sulfo-1, 4-butanediol, and the like.

Constituent Unit represented by formula (I)

The specific polymer 1 preferably contains a constituent unit represented by the following formula (I).

The constitutional unit represented by the formula (I) can be introduced into the specific polymer 1 by using a polycarboxylic acid compound such as sodium dimethyl 5-sulfoisophthalate, sodium dimethyl 2-sulfoterephthalate, or sodium 2-sulfoterephthalate as a monomer component for obtaining the specific polymer 1, for example.

[ chemical formula 4]

In the formula (I), Z⁺Is represented by formula (I) and SO₃ ^-Bonded or dissociated counter cations.

In the formula (I), Z⁺Preferably Na⁺、K⁺Or H⁺。

The specific polymer 1 may contain 1 kind alone, or may contain 2 or more kinds of the constituent units represented by the formula (I).

The specific polymer 1 preferably contains the constituent unit represented by the formula (I) in an amount of 1 to 45 mol%, more preferably 1 to 25 mol%, and still more preferably 1 to 15 mol%, based on all constituent units of the specific polymer 1.

Constituent Unit represented by formula (i)

The specific polymer 1 further preferably contains a constituent unit represented by the following formula (i).

By further including the structural unit represented by the formula (i), the HSP value can be easily adjusted, and the adhesion between the polyester substrate and the image formed by the ink containing the colorant and water can be improved.

The constituent unit represented by the formula (i) can be introduced into the specific polymer 1 by using a polycarboxylic acid compound such as phthalic acid, isophthalic acid, terephthalic acid, or an esterified product thereof, as a monomer component for obtaining the specific polymer 1, for example.

[ chemical formula 5]

The specific polymer 1 may contain 1 kind of the monomer or 2 or more kinds of the constituent units represented by the formula (i).

The specific polymer 1 preferably contains the constituent unit represented by the formula (i) in an amount of 5 to 49 mol%, more preferably 25 to 49 mol%, and still more preferably 35 to 49 mol%, based on all constituent units of the specific polymer 1.

Constituent Unit represented by formula (ii)

The specific polymer 1 preferably contains a constituent unit represented by the following formula (ii) from the viewpoint of being able to easily introduce a monomer component having high reactivity during synthesis and from the viewpoint of imparting an emulsifying and dispersing effect.

The constitutional unit represented by the formula (ii) can be introduced into the specific polymer 1 by using a glycol such as diethylene glycol or ethylene glycol as a monomer component for obtaining the specific polymer 1, for example.

[ chemical formula 6]

In the formula (II), R¹¹Represents a 2-valent linking group.

The linking group having a valence of 2 is preferably an alkylene group, an arylene group, an alkylene group having 1 or more ether bonds in the structure, or a combination thereof.

In the present invention, unless otherwise specified, the "alkylene group" may be linear or branched, and some or all of the carbon atoms constituting the alkylene group may be groups having a cyclic structure.

The alkylene group is preferably an alkylene group having 2to 20 carbon atoms, more preferably an alkylene group having 2to 10 carbon atoms, and still more preferably an alkylene group having 2to 4 carbon atoms.

The arylene group is preferably an arylene group having 6 to 20 carbon atoms, more preferably an arylene group having 6 to 10 carbon atoms, and further preferably a phenylene group.

Examples of the constituent unit represented by the formula (ii) include aliphatic diols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butylene glycol, hexylene glycol, and neopentyl glycol; alicyclic diols such as cyclohexanediol and hydrogenated bisphenol a; aromatic diols such as ethylene oxide adduct of bisphenol a and propylene oxide adduct of bisphenol a; and the like are derived from a constituent unit of a diol.

The specific polymer 1 may contain 1 kind of the monomer or 2 or more kinds of the constituent units represented by the formula (ii).

When the specific polymer 1 contains the constituent unit represented by the formula (ii), the constituent unit represented by the formula (ii) is contained in an amount of preferably 1 to 50 mol%, more preferably 10 to 40 mol%, and still more preferably 10 to 35 mol% based on all constituent units of the specific polymer 1.

Constituent Unit represented by formula (iii)

From the viewpoint of improving the adhesion between the polyester base material and an image formed from an ink containing a colorant and water, improving the abrasion resistance of the image, and the like, the specific polymer 1 preferably contains a constituent unit represented by the following formula (iii).

The constituent unit represented by the formula (iii) can be introduced into the specific polymer 1 by using 1, 4-cyclohexanedimethanol, for example, as a monomer component for obtaining the specific polymer 1.

[ chemical formula 7]

In the formula (III), 2-CH₂The bonding position of-O-is not particularly limited, but in the cyclohexane ring structure, it is preferably bonded to carbon atoms at the 1-position and the 4-position, respectively, or bonded to carbon atoms at the 1-position and the 2-position, respectively, and more preferably bonded to carbon atoms at the 1-position and the 4-position, respectively.

When the specific polymer 1 contains the constituent unit represented by the formula (iii), the constituent unit represented by the formula (iii) is contained in an amount of preferably 1 to 50 mol%, more preferably 10 to 40 mol%, and still more preferably 20 to 40 mol% based on all constituent units of the specific polymer 1.

Other constituent units

The specific polymer 1 may contain other constituent units than those described above.

Examples of the other constituent units include polycarboxylic acids having a valence of 3 or more, such as trimellitic acid and anhydrides thereof; polyhydric alcohols having a valence of 3 or more, such as glycerin, trimethylolpropane and pentaerythritol; aliphatic carboxylic acids such as naphthalenedicarboxylic acid, maleic anhydride, fumaric acid, succinic acid, alkenylsuccinic anhydride, and adipic acid; alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid; and the like.

When the specific polymer 1 contains other constituent units, the other constituent units are preferably contained in an amount of more than 0 mol% and 49 mol% or less, more preferably more than 0 mol% and 20 mol% or less, based on all the constituent units of the specific polymer 1.

Polyesteramide copolymer having sulfonic acid group (specific Polymer 2) -

The polyesteramide copolymer having a sulfonic acid group (specific polymer 2) may be a resin synthesized by using a resin having a sulfonic acid group for at least one of a polycarboxylic acid compound, a polyol compound and a polyamine compound, or a resin obtained by introducing a sulfonic acid group into a synthesized polyesteramide copolymer (for example, a polyesteramide copolymer having no sulfonic acid group).

Since the specific polymer 2 contains an amide bond, the hydrolysis resistance tends to be high. Therefore, by including the specific polymer 2, the storage stability of the prepared printing pretreatment liquid is improved.

Specific polymer 2 in the specific polymer 1, a polyesteramide copolymer in which a part of the constituent unit derived from the polyol compound is replaced with a constituent unit derived from the polyamine compound is preferable.

The specific polymer 2 preferably contains a constituent unit represented by the following formula (iv) as a constituent unit derived from the polyamine compound.

The constituent unit represented by the formula (iv) can be introduced into the specific polymer 2 by using a diamine compound such as hexamethylenediamine as a monomer component for obtaining the specific polymer 2, for example.

The diamine compound reacts with the polycarboxylic acid compound to form an amide bond.

[ chemical formula 8]

In the formula (iv), R¹²Represents a 2-valent linking group.

Examples of the linking group having a valence of 2 include an alkylene group, an arylene group, and a combination thereof.

The alkylene group is preferably an alkylene group having 1 to 20 carbon atoms, more preferably an alkylene group having 1 to 10 carbon atoms, and still more preferably an alkylene group having 1 to 8 carbon atoms.

The arylene group is preferably an arylene group having 6 to 20 carbon atoms, more preferably an arylene group having 6 to 10 carbon atoms, and further preferably a phenylene group.

In the formula (iv), hydrogen atoms may be bonded to each of the 2 nitrogen atoms, and the hydrogen atoms may be independently substituted by a substituent. Preferable substituents include alkyl groups.

The structural unit represented by the formula (iv) includes, for example, the following structural units, and is not limited thereto.

[ chemical formula 9]

The specific polymer 2 may contain 1 kind alone, or may contain 2 or more kinds of the constituent units represented by the formula (iv).

When the specific polymer 2 contains the constituent unit represented by the formula (iv), the constituent unit represented by the formula (iv) is contained in an amount of preferably 1 to 49 mol%, more preferably 5 to 20 mol%, and still more preferably 10 to 15 mol% based on all the constituent units of the specific polymer 1.

The specific polymer 2 preferably contains, as a constituent unit derived from the polycarboxylic acid compound, a constituent unit described as a constituent unit constituting the specific polymer 1 and containing a constituent unit represented by the above formula (I).

The preferable embodiment of the constituent unit represented by the formula (I) contained in the specific polymer 2 is the same as that of the constituent unit represented by the formula (I) contained in the specific polymer 1.

The specific polymer 2 preferably contains the constituent unit represented by the formula (I) in an amount of 1 to 45 mol%, more preferably 1 to 25 mol%, and still more preferably 1 to 15 mol%, based on all constituent units of the specific polymer 2.

The specific polymer 2 preferably contains, as a constituent unit derived from the polycarboxylic acid compound, a constituent unit described as a constituent unit constituting the specific polymer 1 and containing a constituent unit represented by the above formula (i).

The preferable embodiment of the constituent unit represented by the formula (i) contained in the specific polymer 2 is the same as that of the constituent unit represented by the formula (i) contained in the specific polymer 1.

The specific polymer 2 preferably contains the constituent unit represented by the formula (i) in an amount of 5 to 49 mol%, more preferably 25 to 49 mol%, and still more preferably 35 to 49 mol%, based on all constituent units of the specific polymer 2.

The specific polymer 2 preferably contains, as a constituent unit derived from the polyol compound, a constituent unit described as a constituent unit constituting the specific polymer 1 and containing a constituent unit represented by the above formula (ii).

The preferable embodiment of the constituent unit represented by the formula (ii) contained in the specific polymer 2 is the same as that of the constituent unit represented by the formula (ii) contained in the specific polymer 1.

When the specific polymer 2 contains the constituent unit represented by the formula (ii), the constituent unit represented by the formula (ii) is contained in an amount of preferably 1 to 30 mol%, more preferably 5 to 25 mol%, and still more preferably 10 to 20 mol% based on all constituent units of the specific polymer 2.

The specific polymer 2 preferably contains, as a constituent unit derived from the polyol compound, a constituent unit described as a constituent unit constituting the specific polymer 1 and containing a constituent unit represented by the above formula (iii).

The preferable embodiment of the constituent unit represented by the formula (iii) contained in the specific polymer 2 is the same as that of the constituent unit represented by the formula (iii) contained in the specific polymer 1.

When the specific polymer 2 contains the constituent unit represented by the formula (iii), the constituent unit represented by the formula (iii) is contained in an amount of preferably 1 to 40 mol%, more preferably 5 to 35 mol%, and still more preferably 10 to 30 mol% based on all constituent units of the specific polymer 2.

The specific polymer 2 may further contain other constituent units than those described above. As the other constituent unit, other constituent units described as constituent units constituting the specific polymer 1 are preferable.

When the specific polymer 2 contains other constituent units, the other constituent units are preferably contained in an amount of more than 0 mol% and 49 mol% or less, and more preferably in an amount of more than 0 mol% and 20 mol% or less, based on all constituent units of the specific polymer 2.

(meth) acrylic resin having sulfonic acid group (specific polymer 3) -

The (meth) acrylic resin having a sulfonic acid group (specific polymer 3) may be a resin synthesized using a (meth) acrylate having a sulfonic acid group, a resin synthesized using a monomer component having a sulfonic acid group copolymerizable with a (meth) acrylate having no sulfonic acid group and a (meth) acrylate, or a resin obtained by introducing a sulfonic acid group into a synthesized (meth) acrylic resin (for example, a (meth) acrylic resin having no sulfonic acid group).

Examples of the (meth) acrylate having a sulfonic acid group include 2-sulfoethyl (meth) acrylate, 3-sulfopropyl (meth) acrylate, methacryloyloxyethylsulfonic acid, and salts thereof.

Examples of the monomer component having a sulfonic acid group copolymerizable with the (meth) acrylic acid ester include 2-acrylamido-2-methylpropanesulfonic acid, vinylsulfonic acid, allylsulfonic acid, styrenesulfonic acid, α -methylstyrene sulfonic acid, vinylbenzylsulfonic acid, 1-allyloxy-2-hydroxypropanesulfonic acid, allyloxypolyethylene glycol (polymerization degree of ethylene glycol moiety: 10) sulfonic acid, and salts thereof.

As the counter ion constituting the salt, sodium ion, potassium ion, and the like are preferable.

Constituent Unit represented by formula (II)

The specific polymer 3 preferably contains a constituent unit represented by the following formula (II).

[ chemical formula 10]

In the formula (II), R¹Represents a hydrogen atom or a methyl group, R²Represents a single bond, an aromatic ring, or an alkylene group which may contain an ester bond, an amide bond, or an oxygen atom, Z⁺Is represented by formula (I) and SO₃ ^-Bonded or dissociated counter cations.

As R²The aromatic ring or the C1-6 alkylene group containing an amide bond is preferable, the C1-6 alkylene group containing an amide bond is more preferable, and the C1-4 alkylene group containing an amide bond is further preferable.

The alkylene group may be further substituted with an alkyl group, a hydroxyl group, or the like.

More specifically, the constituent unit represented by formula (II) is preferably a constituent unit derived from 2-acrylamido-2-methylpropanesulfonic acid, vinylsulfonic acid, allylsulfonic acid, styrenesulfonic acid, or 1-allyloxy-2-hydroxypropanesulfonic acid, and is preferably a constituent unit derived from 2-acrylamido-2-methylpropanesulfonic acid or styrenesulfonic acid from the viewpoint of the ease of the method for synthesizing the polymer.

The specific polymer 3 may contain 1 kind alone, or may contain 2 or more kinds of the constituent units represented by the formula (II).

The specific polymer 3 preferably contains the constituent unit represented by the formula (II) in an amount of 1 to 40 mol%, more preferably 2to 30 mol%, and still more preferably 3 to 15 mol% based on all constituent units of the specific polymer 3.

Constituent Unit represented by formula (III)

From the viewpoint of adjusting the HSP value, the specific polymer 3 preferably contains a constituent unit represented by the following formula (III).

The constituent unit represented by the formula (III) can be introduced into the specific polymer 3 by using, for example, (meth) acrylamide, 4- (meth) acryloylmorpholine, or the like as a monomer component for obtaining the specific polymer 3.

[ chemical formula 11]

In the formula (III), R³Represents a hydrogen atom or a methyl group, R⁴And R⁵Each independently represents a hydrogen atom or an alkyl group which may contain an oxygen atom, R⁴And R⁵May be bonded to form a ring containing an oxygen atom.

And, R⁴And R⁵The alkyl groups represented may be further substituted by alkyl, hydroxy or acetyl groups.

More specifically, the constituent unit represented by formula (III) is preferably a constituent unit derived from (meth) acrylamide, 4- (meth) acryloylmorpholine, 2-hydroxyethyl (meth) acrylamide, diacetone (meth) acrylamide, N-butoxymethyl (meth) acrylamide, N-isopropyl (meth) acrylamide, N-dimethyl (meth) acrylamide, N-diethyl (meth) acrylamide, dimethylaminopropyl (meth) acrylamide, or the like, and more preferably derived from at least 1 constituent unit selected from the group consisting of (meth) acrylamide, 4-acryloylmorpholine, and 2-hydroxyethyl (meth) acrylamide, from the viewpoint of the simplicity of the synthesis method of the polymer.

The specific polymer 3 may contain 1 kind alone, or may contain 2 or more kinds of the constituent units represented by the formula (III).

The specific polymer 3 preferably contains the constituent unit represented by the formula (III) in an amount of 0 to 80 mol%, more preferably 10 to 70 mol%, and still more preferably 30 to 65 mol%, based on all constituent units of the specific polymer 3.

Constituent unit derived from a (meth) acrylate having no sulfonic acid group

The specific polymer 3 may contain a constituent unit derived from a (meth) acrylate having no sulfonic acid group.

Examples of the (meth) acrylate having no sulfonic acid group include alkyl (meth) acrylates having an alkyl group having 1 to 24 carbon atoms; hydroxyl group-containing (meth) acrylates such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and glycerol mono (meth) acrylate; nitrogen atom-containing (meth) acrylates such as dimethylaminoethyl (meth) acrylate and 2-morpholinoethyl (meth) acrylate; and (meth) acrylates having an ether bond such as methoxyethyl (meth) acrylate, 3-methoxybutyl (meth) acrylate, methoxypropylene glycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, and phenoxyethyl (meth) acrylate.

Among them, from the viewpoint of adjusting the glass transition temperature (Tg) of the specific polymer 3, as the (meth) acrylate having no sulfonic acid group, an alkyl (meth) acrylate having no sulfonic acid group is preferable.

The alkyl group in the alkyl (meth) acrylate is preferably 1 to 20 carbon atoms, more preferably 2to 18 carbon atoms, and still more preferably 4 to 12 carbon atoms.

The specific polymer 3 preferably contains 0 to 80 mol%, more preferably 10 to 70 mol%, and still more preferably 20 to 65 mol% of the constituent units derived from the (meth) acrylate ester having no sulfonic acid group, based on all the constituent units of the specific polymer 3.

Other constituent units

The specific polymer 3 may contain other constituent units than those described above.

Examples of the other constituent units include a constituent unit derived from a vinyl monomer such as styrene or α -methylstyrene, a constituent unit derived from (meth) acrylic acid or a salt thereof, and the like.

The specific polymer 3 preferably contains a styrene-derived constituent unit from the viewpoint of simplicity of the synthesis method of the polymer.

The constituent unit derived from styrene is preferably contained in an amount of 10 to 50 mol%, more preferably 15 to 45 mol%, and still more preferably 15 to 35 mol% based on all constituent units of the specific polymer 3.

[ Properties of specific Polymer ]

The specific polymer preferably has a weight average molecular weight of 1,000 to 500,000, more preferably 2,000 to 250,000, and even more preferably 3,000 to 200,000, from the viewpoint of suppressing peeling of an image by an ink containing a colorant and water, and from the viewpoint of ease of removal of viscosity in a taking-out step in a method for producing a polymer.

In the present invention, the weight average molecular weight (Mw) represents a value measured by Gel Permeation Chromatography (GPC) unless otherwise specified.

The measurement apparatus and the measurement conditions are basically the following conditions, but a more appropriate carrier (eluent) and a column suitable for using the carrier may be selected and used according to the type of the polymer.

For other items, refer to JIS K7252-1 to 4: 2008.

the insoluble polymer was measured at a soluble concentration under the following conditions.

-conditions-

Column chromatography: connecting two TOSOH TSKgel Super AWM-H (trade name)

A vector: 10mM LiBr/N-methylpyrrolidone

Measurement temperature: 40 deg.C

Current carrying capacity: 1.0ml/min

Sample concentration: 0.1% by mass

The detector: RI (refractive index) detector

Injection amount: 0.1ml

The specific polymer preferably has a glass transition temperature (Tg) of 30 ℃ or higher, more preferably 40 to 200 ℃, and still more preferably 40 to 180 ℃.

In the present invention, the glass transition temperature of each resin containing a specific polymer can be measured using Differential Scanning Calorimetry (DSC).

The specific measurement method was carried out according to the method described in JIS K7121 (1987) or JIS K6240 (2011). The glass transition temperature in the present invention is an extrapolated glass transition start temperature (hereinafter, also referred to as Tig).

The method for measuring the glass transition temperature will be described more specifically.

When the glass transition temperature was determined, the temperature was maintained at a temperature about 50 ℃ lower than the predicted Tg of the resin until the device was stabilized, and then the heating rate was set as follows: heating at 20 deg.C/min to a temperature about 30 deg.C higher than the temperature at which the glass transition ended, and making a Differential Thermal Analysis (DTA) curve or DSC curve.

The extrapolated glass transition start temperature (Tig), that is, the glass transition temperature Tg in the present invention, is determined as the temperature of the intersection of a straight line extending from the base line on the low temperature side to the high temperature side in the DTA curve or the DSC curve and a line drawn at the point where the gradient of the curve in the stepwise change portion of the glass transition is maximum.

Also, the specific polymer is preferably a water-soluble or water-dispersible polymer.

In the present invention, "water-soluble" refers to a property of being soluble in water at a certain concentration or more. The "water-soluble" is preferably 5g or more (more preferably 10g or more) in 100g of water at 25 ℃.

In the present invention, "water-dispersible" means that a water-insoluble compound does not precipitate in water at 25 ℃. More specifically, "water-dispersible" refers to a state in which a water-insoluble compound forms micelles in water, a state in which the compound is uniformly dispersed in water, and the like.

The specific polymer may be any of a linear polymer, a graft polymer, a star polymer, a network polymer, and the like, and is preferably a linear polymer.

[ specific examples ]

Specific examples of the specific polymer are shown below, but the present invention is not limited thereto.

In the following specific examples, the following tables attached in parentheses to the respective constituent units show the molar contents.

In the following specific examples, -SO₃Na may be SO₃K, may also be-SO₃H, may also be dissociated to-SO₃ ^-。

[ chemical formula 12]

[ chemical formula 13]

[ chemical formula 14]

[ calculation of HSP value ]

In the present invention, the value of Total calculated using HSPiP software (https:// www.pirika.com/JP/HSP/index. html) is defined as "HSP value".

A specific calculation method of the HSP value is as follows.

First, after the structural formula was transformed into a Smiles marker using the structural formula editor software (ChemBioDraw Ultra 13.0), the value of Total was calculated from Y-MB of HSPiP (HSPiP 4th edition 4.1.07).

Next, a method for calculating the HSP value of the polymer will be specifically described.

With respect to the HSP value of the polymer, the HSP value of each constituent unit constituting the polymer is calculated, and the obtained HSP value of each constituent unit is added for each mole fraction.

Hereinafter, a specific calculation method will be described.

First, as shown in tables 1 to 3, each constituent unit is converted into a structural formula for calculating an HSP value according to the structure of the polymer.

Next, after the HSP calculation structural formula was converted into a Smiles label using the structural formula editor software (ChemBioDraw Ultra 13.0), the bonding point "is rewritten" X "in the obtained Smiles label, and the value of Total (that is, the HSP value in the present invention) is calculated from the rewritten Smiles label based on Y-MB of HSPiP (HSPiP 4th edition 4.1.07).

Then, the HSP values of the obtained constituent units (described in tables 1 to 3 below) were added in accordance with the respective mole fractions to calculate the HSP value of the entire polymer.

[ Table 1]

[ Table 2]

[ Table 3]

In the case of the polymer P-1 having the following structure, for example, HSP values of the respective constituent units shown in Table 1 are calculated as follows. The HSP value is obtained by rounding the 2 nd place below the decimal point to the 1 st place below the decimal point.

Constituent unit TPA derived from dimethyl terephthalate (23.3 × 0.41.41) + constituent unit SSIPA derived from sodium dimethyl 5-sulfoisophthalate (35.5 × 0.09.09) + constituent unit DEG derived from diethylene glycol (20.1 × 0.27) + constituent unit CHDM derived from cyclohexanedimethanol (18.8 × 0.23.23) ═ 22.5[ MPa ] ("MPa"), "m^1/2]

[ chemical formula 15]

The specific polymer may be composed of 1 polymer or a mixture of 2 or more polymers.

In the case where the specific polymer is composed of a mixture of 2 or more polymers, the HSP values of all the polymers are calculated by adding the HSP values of the respective constituent units of the respective polymers based on the mole fractions of the respective constituent units.

For example, when X represents the total mole of the constituent units of the polymers P-4 and H-1 and P-4 having the following structures and Y represents the total mole of the constituent units of the polymer H-1, the molar ratio X: Y is 80:20, the molar ratio X is { (23.3 × 0.24) + (22.4 × 0.24) + (35.5 × 0.02) + (20.1 × 0.10) + (18.8 × 0.40) } × 0.8+ { (28.6 × 0.1) + (42.0 × 0.4) + (22.5 × 0.5) } × 0.2 is 23.1.

In addition, as described above, if the HSP value of the mixture as a whole is 18MPa^0.5Above and 30MPa^0.5In the following range, even if some or all of the polymers mixed have an HSP value of 18MPa^0.5Above and 30MPa^0.5In addition to the following ranges, the adhesion between the polyester substrate and an image formed by an ink containing a colorant and water can be obtained.

That is, in the pretreatment liquid for printing according to the present invention, when the HSP value of the entire polymer mixture satisfies 18MPa^0.5Above and 30MPa^0.5The following ranges may include HSP values of 18MPa^0.5Above and 30MPa^0.5Polymers outside the following ranges.

However, from the viewpoint of improving the adhesion between the polyester substrate and the image formed by the ink containing the colorant and water, it is more preferable that all the polymers to be mixed have an HSP value of 18MPa^0.5Above and 30MPa^0.5Within the following ranges.

[ chemical formula 16]

[ content ]

The printing pretreatment liquid according to the present invention preferably contains the specific polymer in an amount of 1 to 25% by mass, more preferably 3 to 15% by mass, and still more preferably 5 to 10% by mass, based on the total mass of the printing pretreatment liquid, from the viewpoint of improving the adhesion between the polyester substrate and the image formed by the ink containing the colorant and water.

[ Water ]

The printing pretreatment liquid according to the present invention contains water.

The content of water is preferably 50 to 95% by mass, more preferably 60 to 90% by mass, and still more preferably 70 to 85% by mass, based on the total mass of the printing pretreatment liquid.

[ flocculant ]

The printing pretreatment liquid according to the present invention further comprises at least 1 coagulant selected from the group consisting of polyvalent metal salts, organic acids, cationic compounds, and metal complexes.

Details of each component will be described later.

When the pre-treatment liquid for printing contains a coagulant and is mixed with an ink containing a colorant and water, an image having excellent image quality can be easily obtained.

Further, it is considered that by using the specific polymer and the coagulant together, leakage of the coagulant in the obtained printed matter is suppressed, and transfer of components contained in the printing pretreatment liquid such as the coagulant is suppressed. Although the mechanism of the inhibition of the transfer is not clear, it is presumed that the transfer of the coagulant is inhibited particularly because the affinity between the specific polymer and the coagulant is high.

In the pre-treatment liquid for printing according to the present invention, the mass ratio of the content a of the specific polymer to the content B of the coagulant in the pre-treatment liquid for printing is preferably 100:4 to 1:3, more preferably 100:6 to 1:2.5, and still more preferably 10:1 to 1:2, from the viewpoints of improving the image quality of the obtained printed matter and suppressing transfer of components contained in the pre-treatment liquid for printing.

The flocculant preferably contains an organic acid from the viewpoint of improving the image quality of the obtained printed matter and the abrasion resistance of the image, and the organic acid preferably contains a dicarboxylic acid.

The details of the coagulant used in the pre-treatment liquid for printing according to the present invention will be described below.

(organic acid)

Examples of the organic acid include organic compounds having an acidic group.

Examples of the acidic group include a phosphoric acid group, a phosphonic acid group, a phosphinic acid group, a sulfuric acid group, a sulfonic acid group, a sulfinic acid group, and a carboxyl group. The acidic group is preferably a phosphoric group or a carboxyl group, and more preferably a carboxyl group, from the viewpoint of the coagulation rate of the ink.

In addition, at least a part of the acidic groups are preferably dissociated in the printing pretreatment liquid.

Organic compounds having a carboxyl group suitable as the organic acid are preferably polyacrylic acid, acetic acid, glycolic acid, malonic acid, malic acid (preferably DL-malic acid), maleic acid, ascorbic acid, succinic acid, glutaric acid, fumaric acid, citric acid, tartaric acid, phthalic acid, 4-methylphthalic acid, lactic acid, sulfonic acid, orthophosphoric acid, pyrrolidone carboxylic acid, pyrone carboxylic acid, pyrrole carboxylic acid, furan carboxylic acid, pyridine carboxylic acid, coumaric acid, thiophene carboxylic acid, nicotinic acid, derivatives of these compounds, salts of these compounds, and the like. These compounds may be used in 1 kind, or 2 or more kinds may be used simultaneously.

The organic compound having a carboxyl group is preferably a carboxylic acid having a valence of 2 or more (hereinafter, also referred to as a polycarboxylic acid), more preferably a dicarboxylic acid or a tricarboxylic acid, and still more preferably a dicarboxylic acid, from the viewpoint of the coagulation rate of the ink.

The dicarboxylic acid and tricarboxylic acid are preferably malonic acid, malic acid, maleic acid, succinic acid, glutaric acid, fumaric acid, tartaric acid, 4-methylphthalic acid, or citric acid, and more preferably malonic acid, malic acid, glutaric acid, tartaric acid, or citric acid.

The organic acid preferably has a low pKa (e.g., 1.0 to 5.0).

The organic acid having a low pKa can reduce the surface charge of particles such as pigment and polymer particles in the ink, which are dispersed and stabilized with a weakly acidic functional group such as a carboxyl group, by contacting the particles. As a result, since the dispersion stability of the particles can be lowered, an organic acid having a low pKa is preferable as the coagulant.

The organic acid contained in the printing pretreatment liquid is preferably an organic acid having a low pKa, a high solubility in water, and a valence of 2 or more, and more preferably an organic acid having a valence of 2 or 3, which has a high buffering capacity in a pH region lower than the pKa of a functional group (for example, a carboxyl group or the like) for stabilizing the dispersion of particles in the ink.

When an organic acid is used as the coagulant, the content of the organic acid is preferably 1 to 20 mass%, more preferably 2to 15 mass%, and still more preferably 5 to 10 mass% based on the total mass of the pre-treatment liquid for printing according to the present invention.

(polyvalent Metal salt)

The polyvalent metal salt is composed of a polyvalent metal ion having a valency of two or more and an anion bonded to the polyvalent metal ion. Also, the polyvalent metal salt is preferably water-soluble.

Specific examples of the polyvalent metal ion include Ca²⁺、Cu²⁺、Ni²⁺、Mg²⁺、Zn²⁺、Ba²⁺Divalent metal ion of Al³⁺、Fe³⁺、Cr³⁺And (4) trivalent metal ions are obtained. Examples of the anion include Cl^-、NO₃ ^-、I^-、Br^-、ClO₃ ^-、SO₄ ^2-Carboxylic acid ions, and the like.

The polyvalent metal ion and the anion can be combined arbitrarily.

The polyvalent metal salt preferably contains Ca from the viewpoint of improving the image quality of the obtained printed matter²⁺Or Mg²⁺And salts thereof.

Further, as the polyvalent metal salt, sulfate ion (SO) is preferable₄ ^2-) Nitrate ion (NO)₃ ^-) Or carboxylic acid ions (RCOO)^-And R is an alkyl group having 1 or more carbon atoms).

The carboxylic acid ion is preferably an ion derived from a saturated aliphatic monocarboxylic acid having 1 to 6 carbon atoms or a carbocyclic monocarboxylic acid having 7 to 11 carbon atoms. Preferred examples of the saturated aliphatic monocarboxylic acid having 1 to 6 carbon atoms include formic acid, acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, isovaleric acid, pivalic acid, and hexanoic acid.

Preferable polyvalent metal salts include, for example, calcium salts or magnesium salts of sulfuric acid, and in addition, calcium salts or magnesium salts of monocarboxylic acids such as formic acid and acetic acid, calcium salts or magnesium salts of nitric acid, calcium chloride, and magnesium chloride.

When a polyvalent metal salt is used as the coagulant, the content of the polyvalent metal salt is preferably 1 to 40% by mass, more preferably 2to 25% by mass, and still more preferably 5 to 20% by mass, based on the total mass of the printing pretreatment liquid according to the present invention.

(cationic Compound)

The cationic compound is preferably a primary, secondary or tertiary amine salt type compound, for example. Examples of the amine salt type compound include compounds such as hydrochloride or acetate (for example, laurylamine, cacao amine, stearylamine, rosin amine, etc.), quaternary ammonium salt type compounds (for example, lauryltrimethylammonium chloride, cetyltrimethylammonium chloride, lauryldimethylbenzylammonium chloride, benzyltributylammonium chloride, benzalkonium chloride, etc.), pyridinium salt type compounds (for example, cetylpyridinium chloride, cetylpyridinium bromide, etc.), imidazoline type cationic compounds (for example, 2-heptadecenyl-hydroxyethylimidazoline, etc.), and ethylene oxide adducts of higher alkylamines (for example, dihydroxyethylstearylamine, etc.). As the amine salt type compound, polyallylamine (i.e., polyallylamine or a polyallylamine derivative) can be used.

The polyallylamine or polyallylamine derivative is not particularly limited, and known materials can be appropriately selected and used, and examples thereof include polyallylamine hydrochloride, polyallylamine amide sulfate, copolymer of allylamine hydrochloride/diallylamine hydrochloride, copolymer of allylamine acetate/diallylamine acetate, copolymer of allylamine hydrochloride/dimethylallylamine hydrochloride, copolymer of allylamine/dimethylallylamine, polydiallylamine hydrochloride, polydiallylamine amide sulfate, polydiallylamine acetate, polydiallyldimethylammonium chloride, copolymer of diallylamine acetate/sulfur dioxide, copolymer of diallylmethylethylammonium sulfate/sulfur dioxide, copolymer of methyldiallylamine hydrochloride/sulfur dioxide, copolymer of polyallylamine acetate/sulfur dioxide, polyallylamine hydrochloride/diallyl chloride/, Diallyl dimethyl ammonium chloride-sulfur dioxide copolymer, diallyl dimethyl ammonium chloride-acrylamide copolymer, and the like.

As such polyallylamine or polyallylamine derivatives, commercially available products can be used, for example, "PAA-HCL-01", "PAA-HCL-03", "PAA-HCL-05", "PAA-HCL-3L", "PAA-HCL-10L", "PAA-H-HCL", "PAA-SA", "PAA-01", "PAA-03", "PAA-05", "PAA-08", "PAA-15C", "PAA-25", "PAA-H-10C", "PAA-D11-HCL", "PAA-D41-HCL", "PAA-D19-HCL", "PAS-21 CL", "PAS-M-1L", "PAS-M-1", "PAS-22 SA "PAS-M-1A", "PAS-H-1L", "PAS-H-5L", "PAS-H-10L", "PAS-92A", "PAS-J-81L", "PAS-J-81" (all trade names, NITTOBO MEDICAL CO., LTD.), "HIMONeo-600", "HIMOLOCK Q-101", "HIMOLOCK Q-311", "HIMOLOCK Q-501", "HIMAX SC-505" (all trade names, HYMO CO., LTD.), and the like.

When a cationic compound is used as the coagulant, the content of the cationic compound is preferably 1 to 40% by mass, more preferably 2to 25% by mass, and still more preferably 5 to 20% by mass, based on the total mass of the printing pretreatment liquid according to the present invention.

(Metal Complex)

In the present invention, the metal complex is a compound in which a ligand is coordinated to a metal ion such as a zirconium ion, a titanium ion, or an aluminum ion.

As the metal complex used in the printing pretreatment liquid according to the present invention, various commercially available metal complexes can be used.

Also, various polydentate ligands capable of forming various organic ligands, particularly capable of forming metal chelate catalysts, are commercially available. Therefore, as the metal complex, a metal complex prepared by combining a commercially available organic ligand and a metal can be used.

Examples of the metal complex include zirconium tetraacetylacetonate (e.g., Matsumoto Fine Chemical co., ltd. "Orgatix ZC-150"), zirconium monoacetylacetonate (e.g., Matsumoto Fine Chemical co., ltd. "Orgatix ZC-540"), zirconium bisacetylacetonate (e.g., Matsumoto Fine Chemical co., ltd. "Orgatix ZC-550"), zirconium monoethylacetoacetate (e.g., Matsumoto Fine Chemical co., ltd. "Orgatix ZC-560"), zirconium acetate (e.g., Matsumoto Fine Chemical co., ltd. "Orgatix ZC-115"), titanium diisopropoxybis (e.g., Matsumoto Fine Chemical co., ltd. "Orgatix ZC-100"), titanium tetraacetylacetonate (e.g., Matsumoto co., ltd. "Orgatix ZC.," Orgatix-100 "), titanium tetraacetylacetonate (e.g., Matsumoto Fine Chemical co., ltd." Orgatix ZC., "Orgatix mic TC"), titanium dioctanolate (e.g., titanium dioctanolate TC. "200") Diisopropoxybis bis (titanium ethylacetoacetate) (e.g., Matsumoto Fine Chemical co., ltd. "Orgatix TC-750"), zirconium tetraacetylacetonate (e.g., Matsumoto Fine Chemical co., ltd. "Orgatix ZC-700"), zirconium tributoxyacetoacetonate (e.g., Matsumoto Fine Chemical co., ltd. "Orgatix ZC-540"), zirconium mono-butoxyacetylacetonate bis (e.g., Matsumoto Fine Chemical co., ltd. "Orgatix ZC-570"), zirconium dibutoxybis (ethylacetoacetate) (e.g., Matsumoto Fine Chemical co., ltd. "Orgatix ZC-570"), aluminum triacetylacetonate (e.g., Matsumoto Fine co., ltd. "Orgatix ZC-580"), titanium ammonium lactate (e.g., Matsumoto co., ltd. "Orgatix l-80"), titanium ammonium lactate (e.g., Matsumoto Fine co., ltd. "Orgatix TC-300"), aluminum monoacetylacetonate, 315 "), titanium triethanolamine (matsumotopine Chemical co., ltd." Orgatix TC-400 "), matsumotopine Chemical co., ltd." Orgatix ZC-126 ".

Among these, titanium ammonium lactate (Matsumoto Fine Chemical co., ltd. "Orgatix TC-300"), titanium lactate (Matsumoto Fine Chemical co., ltd. "Orgatix TC-310, 315"), titanium triethanolamine (Matsumoto Fine Chemical co., ltd. "Orgatix TC-400"), Matsumoto Fine Chemical co., ltd. "Orgatix ZC-126") are preferable.

(Hansen solubility parameter of coagulant)

The coagulant preferably has a Hansen solubility parameter value (HSP value) of 15MPa^1/2Above and 80MPa^1/2The following.

When the HSP value of the coagulant is in the above range, the adhesion between the polyester substrate and the image formed by the ink containing the colorant and water is further improved.

The HSP value of the coagulant is more preferably 20MPa^1/2Above and 60MPa^1/2Hereinafter, more preferably 25MPa^1/2Above 40MPa^1/2The following.

Here, the HSP value of the coagulant is calculated by the aforementioned method.

Preferred examples of the coagulant having an HSP value in the above range are shown below. In addition, values in parentheses indicate HSP values.

Organic acid: malonic acid (32.5 MPa)^1/2) Glutaric acid (28.1 MPa)^1/2)

Polyvalent metal salt: magnesium sulfate (64.9 MPa)^1/2)

Cationic compound: polyallylamine (19.8 MPa)^1/2)

[ other Components ]

(Water-soluble solvent)

The printing pretreatment liquid may include at least 1 water-soluble solvent.

As the water-soluble solvent, a known water-soluble solvent can be used without particular limitation.

Examples of the water-soluble solvent include glycols such as glycerin, 1,2, 6-hexanetriol, trimethylolpropane, ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, pentaethylene glycol, and dipropylene glycol; polyhydric alcohols such as alkanediols such as 2-butene-1, 4-diol, 2-ethyl-1, 3-hexanediol, 2-methyl-2, 4-pentanediol, 1, 2-octanediol, 1, 2-hexanediol, 1, 2-pentanediol, and 4-methyl-1, 2-pentanediol; saccharides or sugar alcohols, hyaluronic acids, alkyl alcohols having 1 to 4 carbon atoms, glycol ethers, 2-pyrrolidone, N-methyl-2-pyrrolidone, and the like described in paragraph 0116 of Japanese patent application laid-open No. 2011-042150.

Among them, from the viewpoint of suppressing image peeling, polyalkylene glycols among ethers or derivatives thereof are preferable, and at least 1 selected from the group consisting of diethylene glycol monoalkyl ether, triethylene glycol monoalkyl ether, dipropylene glycol, tripropylene glycol monoalkyl ether, polyoxypropylene glycerol ether, and polyoxyethylene polyoxypropylene glycol is more preferable.

When the printing pretreatment liquid contains a water-soluble solvent, the content of the water-soluble solvent is preferably 3 to 20 mass%, more preferably 5 to 15 mass%, based on the total mass of the printing pretreatment liquid, from the viewpoint of coatability and the like.

(surfactant)

The printing pretreatment liquid may include at least 1 kind of surfactant.

Surfactants can be used as surface tension modifiers or defoamers.

Examples of the surface tension adjusting agent and the defoaming agent include nonionic surfactants, cationic surfactants, anionic surfactants, and betaine surfactants. Among them, from the viewpoint of the coagulation rate of the ink, a nonionic surfactant or an anionic surfactant is preferable.

As the surfactant, there may be mentioned those exemplified as surfactants in Japanese patent application laid-open No. Sho 59-157636, pages 37 to 38 and Research Disclosure No.308119 (1989). Further, fluorine (fluoroalkyl) surfactants and silicone surfactants described in each of Japanese patent application laid-open Nos. 2003-322926, 2004-325707, and 2004-309806 can be cited.

The content of the surfactant in the printing pretreatment liquid is not particularly limited, but the surface tension of the printing pretreatment liquid is preferably 50mN/m or less, more preferably 20mN/m to 50mN/m, and still more preferably 30mN/m to 45 mN/m.

(other additives)

The printing pretreatment liquid may contain other components than those described above as necessary.

Examples of other components that can be contained in the pre-treatment liquid for printing include known additives such as a solid wetting agent, colloidal silica, an inorganic salt, an anti-fading agent, an emulsion stabilizer, a penetration enhancer, an ultraviolet absorber, an antiseptic, an anti-mold agent, a pH adjuster, a viscosity adjuster, an anti-rust agent, and a chelating agent.

[ physical Properties of printing pretreatment liquid ]

From the viewpoint of the coagulation rate of the ink, the pH of the printing pretreatment liquid at 25 ℃ is preferably 0.1 to 3.5.

When the pH of the printing pretreatment liquid is 0.1 or more, the roughness of the polyester substrate can be further reduced, and the adhesion of the image portion can be further improved.

When the pH of the printing pretreatment liquid is 3.5 or less, the coagulation rate is further increased, and the aggregation of dots (i.e., ink dots) caused by the ink on the polyester substrate can be further suppressed, whereby the roughness of the image can be further reduced.

The pH (25 ℃) of the printing pretreatment liquid is more preferably 0.2 to 2.0.

The viscosity of the printing pretreatment liquid is preferably in the range of 0.5 to 10 mPas, more preferably 1 to 5 mPas, from the viewpoint of the aggregation speed of the ink.

The viscosity of the printing pretreatment liquid was measured at 25 ℃ using a VISCOMETER TV-22(TOKI SANGYO CO., LTD.).

The surface tension of the printing pretreatment liquid at 25 ℃ is preferably 60mN/m or less, more preferably 20mN/m to 50mN/m, and still more preferably 30mN/m to 45 mN/m.

When the surface tension of the printing pretreatment liquid is within the range, the adhesion between the polyester substrate and the printing pretreatment liquid is improved.

The Surface tension of the printing pretreatment liquid was measured by a plate method using an Automatic Surface densitometer CBVP-Z (Kyowa Interface Science Co., Ltd.).

< substrate for printing >

The printing substrate according to the present invention comprises a polyester substrate and a treatment layer containing a solid component of the printing pretreatment liquid according to the present invention provided on at least one surface of the polyester substrate.

[ polyester substrate ]

The polyester substrate is any of a substrate containing a polyester resin as a main component and a substrate whose surface is coated with a polyester resin.

As the polyester substrate, in particular, a polyethylene terephthalate (i.e., PET) substrate is preferable.

The polyester substrate has impermeability such that it absorbs little or no water contained in the ink, specifically, the amount of water absorbed is 10.0g/m²The following substrates.

The amount of water absorbed by the polyester substrate can be obtained by measuring the mass of water absorbed in a region of 100mm × 100mm on the image recording surface of the polyester substrate in contact with water and holding the polyester substrate at 25 ℃ for 1 minute, and calculating the amount of water absorbed per unit area.

The form of the polyester substrate is not particularly limited, and examples thereof include a sheet form and a film form.

From the viewpoint of productivity of printed matter, the form of the polyester substrate is preferably a long sheet or film wound in a roll.

The polyester substrate may be surface treated.

Examples of the surface treatment include, but are not limited to, corona treatment, plasma treatment, flame treatment, heat treatment, abrasion treatment, and light irradiation treatment (for example, UV treatment).

For example, if the surface of the polyester substrate is subjected to corona treatment in advance before ink is applied and an image is recorded, the surface energy of the polyester substrate increases and wetting of the surface of the polyester substrate and ink adhesion to the polyester substrate are promoted. The Corona treatment can be performed using, for example, a Corona Master (Shinko Electric & Instrumentation co., ltd., PS-10S) or the like.

The conditions for the corona treatment may be appropriately selected depending on the kind of the polyester substrate, the composition of the ink, and the like. For example, the following process conditions may be set.

Processing voltage: 10-15.6 kV

Processing speed: 30 to 100mm/s

[ treatment layer ]

The printing substrate according to the present invention has a treatment layer containing a solid content of the printing pretreatment liquid according to the present invention.

That is, the treated layer in the printing substrate is a layer containing a water-soluble polymer compound, a surfactant, other additives, and the like as necessary, in addition to the above-described specific polymer and the coagulant.

The treatment layer may be formed on at least a part of the surface on which the printing substrate is printed, and examples thereof include a system formed on the entire surface of the printed surface and a system formed at a position other than an end portion (i.e., a non-printed portion) of the printed surface.

When the polyester substrate is in the form of a sheet or a film, the treated layer may be formed on one surface or both surfaces of the polyester substrate.

In the present invention, the treatment layer may be a continuous layer, a discontinuous layer, or a layer having a non-uniform thickness.

The thickness of the treated layer containing the solid component is preferably 0.01 to 10 μm, and more preferably 0.05 to 1 μm.

The thickness of the treatment layer can be measured by cutting the printing substrate and observing the cut surface with a scanning electron microscope. Specifically, the thickness is measured at any 5 points by cooling the sample with liquid nitrogen, thinning the sample with a microtome, and measuring the thickness of the cross section. The thickness of the treated layer was set to the average of the measured thicknesses at 5.

The treated layer preferably contains no water or water in an amount of more than 0 mass% and 20 mass% or less with respect to the total mass of the treated layer, and more preferably contains no water or water in an amount of more than 0 mass% and 5 mass% or less with respect to the total mass of the solid components.

The content of water is measured by the following karl fischer method.

The water content (mg) was measured using a Karl Fischer titration apparatus (a Coulometric titration type water content measuring apparatus model Mitsubishi Chemical Analytec CA-06), and the water content (%) was calculated from the following formula (A). The measurement sample refers to a sample taken out from the treatment layer.

Water content (%) ([ water content (mg)/measurement sample (mg) ] × 100 formula (a)

Detailed conditions for the assay are set forth in JISK 0113: reference numeral 2005.

The treatment layer is obtained by, for example, drying the printing pretreatment liquid according to the present invention.

Here, the drying means removing at least a part of water contained in the printing pretreatment liquid.

The drying method is not particularly limited, and examples thereof include drying by heating, drying by air blowing, and natural drying.

The amount of the specific polymer in the printing substrate is preferably 0.1g/m from the viewpoint of improving the adhesion of an image and suppressing the peeling of an image²～3.0g/m²More preferably 0.3g/m²～2.0g/m²The amount of (c).

< method for producing substrate for printing >

The method for producing a printing substrate according to the present invention includes a step of applying the printing pretreatment liquid according to the present invention to a polyester substrate (hereinafter, also referred to as a pretreatment liquid applying step).

The method for producing a printing substrate preferably includes a step (hereinafter, also referred to as a drying step) of drying the applied printing pretreatment liquid after the step of applying the printing pretreatment liquid (i.e., the pretreatment liquid applying step).

[ pretreatment liquid imparting step ]

The pretreatment liquid application step in the method for producing a printing substrate can be performed by applying a known method such as a coating method, an ink-jet method, or a dipping method.

The coating method can be performed by using a known coating method such as a bar coater, an extrusion die coater, an air knife coater, a blade coater, a bar coater, a knife coater, a squeeze coater, or a reverse roll coater.

The details of the ink jet method are the same as those of the ink jet method in the image recording step described later.

[ drying procedure ]

The drying of the printing pretreatment liquid in the method for producing a printing substrate may be any of drying by heating, drying by air blowing, and natural drying, and is preferably drying by heating.

Examples of the means for heating and drying include known heating means such as a heater, known air blowing means such as a dryer, and a combination thereof.

The heating temperature at the time of heating and drying is preferably 60 ℃ or higher, more preferably 65 ℃ or higher, and particularly preferably 70 ℃ or higher.

The upper limit of the heating temperature is not particularly limited, and examples of the upper limit include 100 ℃ and preferably 90 ℃.

< ink set >

The ink set according to the present invention contains an ink composition containing a colorant and water, and the printing pretreatment liquid according to the present invention.

Specifically, for example, there may be mentioned 4-color ink compositions of cyan, magenta, yellow and black, and the ink set of the printing pretreatment liquid according to the present invention.

The ink composition contained in the ink set according to the present invention will be described in detail below.

[ ink composition ]

The ink composition contained in the ink set according to the present invention will be described below.

The ink composition is preferably an aqueous ink containing a colorant and water.

In the present invention, the aqueous ink is an ink composition containing 50% by mass or more of water based on the total mass of the ink.

The content of the organic solvent in the ink composition is preferably 40% by mass or less, and more preferably 30% by mass or less, based on the total mass of the ink composition.

The ink composition preferably contains no polymerizable compound, or contains more than 0% by mass and 10% by mass or less of polymerizable compound, and more preferably contains no polymerizable compound.

Examples of the polymerizable compound include a cationic polymerizable compound and a radical polymerizable compound.

(coloring agent)

The ink composition contains a colorant.

The colorant is not particularly limited, and colorants known in the field of inkjet inks can be used, but organic pigments or inorganic pigments are preferred.

Examples of the organic pigment include azo pigments, polycyclic pigments, dye chelates, nitro pigments, nitroso pigments, and aniline black. Among these, azo pigments, polycyclic pigments and the like are more preferable.

Examples of the inorganic pigment include titanium oxide, iron oxide, calcium carbonate, barium sulfate, aluminum hydroxide, barium yellow, cadmium red, chrome yellow, and carbon black. Among these, carbon black is particularly preferable.

Examples of the colorant include colorants described in paragraphs 0096 to 0100 of Japanese patent application laid-open No. 2009-241586.

The content of the colorant is preferably 1 to 25% by mass, more preferably 2to 20% by mass, still more preferably 5 to 20% by mass, and particularly preferably 5 to 15% by mass, based on the total mass of the ink composition.

(Water)

The ink composition contains water.

The content of water is preferably 50 to 90% by mass, and more preferably 60 to 80% by mass, based on the total mass of the ink composition.

(dispersing agent)

The ink composition may contain a dispersant for dispersing the above colorant.

The dispersant may be any of a polymer dispersant and a low-molecular surfactant-type dispersant. The polymer dispersant may be either a water-soluble dispersant or a water-insoluble dispersant.

As the dispersant, for example, the dispersants described in paragraphs 0080 to 0096 of Japanese patent laid-open publication No. 2016-145312 are preferable.

The mixing mass ratio (p: s) of the colorant (p) and the dispersant(s) is preferably in the range of 1:0.06 to 1:3, more preferably in the range of 1:0.125 to 1:2, and still more preferably in the range of 1:0.125 to 1: 1.5.

(resin particles)

The ink composition preferably contains at least 1 kind of resin particles.

The resin particles can further improve mainly the fixing property to the polyester substrate of the ink composition and the scratch resistance of the image. The resin particles are aggregated or destabilized in dispersion when they come into contact with the aggregating agent, and thereby thicken the ink composition, thereby providing the ink composition (i.e., an image obtained from the ink composition) with a function of fixing. The resin particles are preferably dispersed in water or a mixture of water and an organic solvent.

The resin particles are preferably those described in paragraphs 0062 to 0076 of Japanese patent application laid-open No. 2016-188345.

(Water-soluble organic solvent)

The ink composition used in the present invention preferably contains at least 1 kind of water-soluble organic solvent.

By using the water-soluble organic solvent, the effect of preventing drying and wetting of the ink composition can be obtained. The water-soluble organic solvent serves as an anti-drying agent to prevent the ink composition from adhering and drying at the ink ejection port of the ejection nozzle to form aggregates to clog the nozzle. In addition, in preventing drying and wetting of the ink composition, a water-soluble organic solvent having a vapor pressure lower than that of water is preferable.

The anti-drying agent is preferably a water-soluble organic solvent having a vapor pressure lower than that of water. Specific examples of such water-soluble organic solvents include polyhydric alcohols typified by ethylene glycol, propylene glycol, diethylene glycol, polyethylene glycol, thiodiethylene glycol, dithiodiethylene glycol, 2-methyl-1, 3-propanediol, 1,2, 6-hexanetriol, acetylene glycol derivatives, glycerin, trimethylolpropane, and the like.

Among them, polyhydric alcohols such as glycerin and diethylene glycol are preferable as the anti-drying agent.

The anti-drying agent can be used alone 1 kind, or simultaneously more than 2 kinds.

The content of the anti-drying agent is preferably in the range of 10 to 50 mass% with respect to the total mass of the ink composition.

The water-soluble organic solvent is used for adjusting the viscosity in addition to the above-mentioned purpose.

Specific examples of the water-soluble organic solvent that can be used for adjusting the viscosity include alcohols (e.g., methanol, ethanol, propanol, isopropanol, butanol, isobutanol, sec-butanol, tert-butanol, pentanol, hexanol, cyclohexanol, benzyl alcohol), polyhydric alcohols (e.g., ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, butylene glycol, hexylene glycol, pentanediol, glycerol, hexanetriol, thiodiglycol), glycol derivatives (e.g., ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monobutyl ether, dipropylene glycol monomethyl ether, triethylene glycol monomethyl ether, ethylene glycol diacetate, ethylene glycol monomethyl ether acetate, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, ethylene glycol monophenyl ether), and the like, Amines (e.g., ethanolamine, diethanolamine, triethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, morpholine, N-ethylmorpholine, ethylenediamine, diethylenetriamine, triethylenetetramine, polyethyleneimine, tetramethylpropylenediamine) and other polar solvents (e.g., formamide, N-dimethylformamide, N-dimethylacetamide, dimethyl sulfoxide, sulfolane, 2-pyrrolidone, N-methyl-2-pyrrolidone, N-vinyl-2-pyrrolidone, 2-oxazolidinone, 1, 3-dimethyl-2-imidazolidinone, acetonitrile, acetone).

When the solvent is used for adjusting the viscosity, not only 1 kind of solvent but also 2 or more kinds of water-soluble organic solvents may be used together.

(other additives)

The ink composition can be formed using other additives in addition to the above components.

Examples of the other additives include known additives such as a drying inhibitor (also referred to as a wetting agent), a fading inhibitor, an emulsion stabilizer, a penetration enhancer, an ultraviolet absorber, a preservative, a fungicide, a pH adjuster, a surface tension adjuster, a defoaming agent, a viscosity adjuster, a dispersant other than the above, a dispersion stabilizer, a rust inhibitor, and a chelating agent.

< image recording method >

An image recording method according to the present invention includes: a step of applying the printing pretreatment liquid according to the present invention to the surface of the polyester substrate (hereinafter, also referred to as "pretreatment liquid applying step"); and a step of recording an image by ejecting an ink composition containing a colorant and water onto the surface to which the printing pretreatment liquid is applied by an ink jet method (hereinafter, also referred to as "image recording step").

[ pretreatment liquid imparting step ]

The pretreatment liquid application step in the image recording method can be performed by applying a known method such as an application method, an ink jet method, or a dipping method.

The coating method can be performed by using a known coating method such as a bar coater, an extrusion die coater, an air knife coater, a blade coater, a bar coater, a knife coater, a squeeze coater, or a reverse roll coater.

The details of the ink jet method are the same as those of the ink jet method in the image recording step described later.

The amount of the pre-treatment liquid for printing is not particularly limited as long as the ink composition can aggregate, but is preferably 0.05g/m from the viewpoint of improving the adhesion of an image and suppressing the peeling of an image after drying the pre-treatment liquid for printing²The amount of the above-mentioned components is more preferably 0.05g/m after drying the printing pretreatment liquid²～1.0g/m²The amount of (c).

Further, the polyester substrate may be heated before the printing pretreatment liquid is applied.

The heating temperature may be appropriately set according to the kind of the polyester substrate, the composition of the printing pretreatment liquid, and the like, and is preferably 30 to 70 ℃, more preferably 30 to 60 ℃.

The polyester substrate used in the image recording method according to the present invention may be a polyester substrate subjected to a surface treatment as needed, or may be a polyester substrate not subjected to a surface treatment and subjected to a surface treatment before the application of the printing pretreatment liquid in the pretreatment liquid applying step.

The surface treatment includes the treatment described as the surface treatment of the polyester substrate in the printing substrate according to the present invention, and these treatments can be performed by a known method.

[ image recording procedure ]

In the image recording step in the image recording method, an ink composition containing a colorant and water is ejected by an ink jet method onto the surface of the printing pretreatment liquid to which the polyester substrate is applied, thereby recording an image.

That is, the image recording step is a step of applying the ink composition to the polyester substrate by an ink jet method.

In this step, an ink (that is, an ink composition containing a colorant and water) can be selectively applied to the polyester substrate (specifically, the surface of the polyester substrate to which the printing pretreatment liquid is applied), and a desired visible image can be formed.

As the ink composition used in the image recording step, the ink composition contained in the ink set according to the present invention can be preferably used.

Image formation by the ink jet method forms a colored image by ejecting ink onto a desired polyester substrate by imparting energy.

Further, as an ink jet method preferable in the present invention, the methods described in paragraphs 0093 to 0105 of jp 2003-306623 a can be applied.

The ink jet method is not particularly limited, and may be a known method, and examples thereof include a charge control method for ejecting ink by utilizing an electrostatic induction force; a drop-on-demand ink jet system (also referred to as a pressure pulse system) using the vibration pressure of a piezoelectric element; an acoustic inkjet method in which an electric signal is changed into an acoustic beam, the acoustic beam is irradiated to ink, and the ink is ejected by radiation pressure; and a thermal ink Jet (also referred to as a Bubble Jet (registered trademark)) system that heats ink to form bubbles and uses the generated pressure. As the ink jet method, the following ink jet methods can be effectively used in particular: in the method described in jp 54-059936 a, the ink subjected to the action of thermal energy undergoes a rapid volume change, and the ink is ejected from the nozzle by the urging force generated by the state change.

There are a shuttle system in which recording is performed while scanning a short serial head (serial head) as an ink jet head in the width direction of the polyester base material, and a line system in which recording elements are arranged corresponding to the entire region of 1 side of the polyester base material. In the line system, image recording can be performed on the entire surface of the polyester base material by scanning the polyester base material in a direction intersecting the array direction of the recording elements, and a transport system such as a carriage (carriage) that scans a short head is not required. Further, since only the polyester base material is moved without performing the movement of the carriage and the complicated scanning control of the polyester base material, the recording speed can be increased as compared with the shuttle system. The image recording method according to the present invention can be applied to any of these systems, but when applied to a line system in which dummy ejection (dummy ejection) is not generally performed, the effect of improving ejection accuracy and image wear resistance is large.

The amount of ink droplets discharged from the inkjet head is preferably 1pl (picoliter) to 10pl, and more preferably 1.5pl to 6pl, from the viewpoint of obtaining a high-definition image. Further, it is also effective to discharge droplets in combination of different amounts from the viewpoint of improving unevenness of images and continuous gradation connection.

[ drying procedure ]

The image recording method according to the present invention may further include a drying step.

The drying step can be performed at either or both of the timing after the pretreatment liquid applying step and before the image recording step.

As the drying in the drying step, heating drying is preferable.

Examples of the means for heating and drying include known heating means such as a heater, known air blowing means such as a dryer, and a combination thereof.

In the heating step after the image recording step, the image can be heated and dried.

Examples of the method for heating and drying the image include a method of applying heat from the side opposite to the image recording surface of the polyester substrate by a heater or the like, a method of bringing warm air or hot air into contact with the image recording surface of the polyester substrate, a method of applying heat from the image recording surface of the polyester substrate or the side opposite to the image recording surface by an infrared heater, and a method of combining a plurality of these.

The heating temperature at the time of heat drying of the image is preferably 60 ℃ or higher, more preferably 65 ℃ or higher, and particularly preferably 70 ℃ or higher.

The upper limit of the heating temperature is not particularly limited, and examples of the upper limit include 100 ℃ and preferably 90 ℃.

The time for heat-drying the image is not particularly limited, but is preferably 3 seconds to 60 seconds, more preferably 5 seconds to 30 seconds, and particularly preferably 5 seconds to 20 seconds.

< other mode of image recording method >

Another embodiment of the image recording method according to the present invention includes a step of recording an image by discharging an ink composition containing a colorant and water onto the treated layer of the printing substrate according to the present invention by an ink jet method.

The step of ejecting an ink composition containing a colorant and water onto the treatment layer of the printing substrate according to the present invention by an ink jet method and recording an image is the same as that of the image recording step in the image recording method, and preferred embodiments are the same.

Another embodiment of the image recording method may include a drying step. The details of the drying step are the same as those of the drying step in the image recording method described above, and preferred embodiments are also the same.

< image record >)

The image recorded matter according to the present invention comprises a polyester substrate and an image containing the solid content of the printing pretreatment liquid according to the present invention and a colorant provided on the surface of the polyester substrate.

The image recorded matter of the present invention is obtained by the aforementioned image recording method of the present invention.

As described above, the printing pretreatment liquid according to the present invention contains the specific polymer and the coagulant. The colorant supplied from the ink is coagulated by the action of the coagulant of the printing pretreatment liquid, and the adhesion between the colorant and the polyester substrate is improved by the action of the specific polymer, so that the image recorded matter of the present invention is excellent in the adhesion of the image and the image quality.

[ image recording apparatus ]

The image recording apparatus used in the image recording method according to the present invention is not particularly limited as long as it includes an image recording mechanism for performing an ink jet method.

As the image recording means used in the ink jet method, for example, known ink jet recording apparatuses described in japanese patent application laid-open nos. 2010-083021, 2009-234221, and 10-175315 can be used.

An example of an image recording apparatus that can be used in the image recording method according to the present invention will be described below with reference to fig. 1.

The image recording apparatus shown in fig. 1 includes a pretreatment liquid applying mechanism for applying a pretreatment liquid for printing and an image recording mechanism for performing an ink jet method.

Here, fig. 1 is a schematic configuration diagram showing a configuration example of the image recording apparatus.

As shown in fig. 1, the image recording apparatus is arranged in the following order from a supply portion 11 of the polyester substrate toward the transport direction of the polyester substrate (the direction of the arrow in the figure): a printing pretreatment liquid applying section 12 for applying a printing pretreatment liquid to the surface of the polyester substrate; a printing pretreatment liquid drying zone 13 provided with a heating mechanism (not shown) for drying the applied printing pretreatment liquid; an ink ejecting section 14 for dispensing various inks; and an ink drying area 15 for drying the ejected ink.

The polyester substrate supply unit 11 in the image recording apparatus may be a supply unit that supplies a polyester substrate from a case in which the polyester substrate is loaded, or may be a supply unit that supplies a polyester substrate from a roll of a polyester substrate wound in a roll.

The polyester base material is fed from the supply unit 11 to the printing pretreatment liquid application unit 12, the printing pretreatment liquid drying zone 13, the ink discharge unit 14, and the ink drying zone 15 in this order by the feed rollers 41,42, 43, 44, 45, and 46, and is collected in the collection unit 16.

In the accumulating section 16, the polyester substrate may be wound into a roll.

The polyester substrate may be conveyed by a roller conveying method using a roller-shaped member, a conveyor belt conveying method, a flat bed conveying method using a flat bed, or the like, in addition to the method using the conveying roller shown in fig. 1.

At least 1 of the plurality of conveyance rollers 41,42, 43, 44, 45, and 46 can be a driving roller to which power of a motor (not shown) is transmitted.

The polyester substrate is conveyed in a predetermined direction at a predetermined conveying speed by rotating a driving roller rotated by a motor at a constant speed.

The printing pretreatment liquid applying section 12 is provided with an anilox roller 20 disposed by immersing a part of a storage tray storing the printing pretreatment liquid, and an applying roller 22 in contact with the anilox roller 20. The anilox roller 20 is a roller material for supplying a predetermined amount of the printing pretreatment liquid to an application roller 22 disposed opposite to the image recording surface of the polyester substrate. The printing pretreatment liquid is uniformly applied on the polyester substrate by an application roller 22 supplied with an appropriate amount of the pretreatment liquid from an anilox roller 20.

The coating roller 22 is configured to be capable of conveying the polyester substrate in a pair with the counter roller 24, and the polyester substrate is sent to the printing pretreatment liquid drying zone 13 through a gap between the coating roller 22 and the counter roller 24.

A printing pretreatment liquid drying zone 13 is disposed on the downstream side of the printing pretreatment liquid applying section 12 in the transport direction of the polyester substrate.

The printing pretreatment liquid drying zone 13 may include a known heating mechanism such as a heater, an air blowing mechanism such as a dryer, an air knife, or a combination thereof.

Examples of the heating means include a method of providing a heating element such as a heater on the opposite side of the printing pretreatment liquid application surface (i.e., image recording surface) of the polyester substrate (for example, below the conveying means on which the polyester substrate is placed and conveyed in the case of automatically conveying the polyester substrate), a method of bringing warm air or hot air into contact with the printing pretreatment liquid application surface (i.e., image recording surface) of the polyester substrate, and a heating method using an infrared heater. Also, the heating mechanism may combine a plurality of the above methods.

In the printing pretreatment liquid drying zone 13, the solvent may be removed from the printing pretreatment liquid using a solvent removal roller or the like.

The ink ejection section 14 is disposed on the downstream side in the conveyance direction of the polyester substrate in the printing pretreatment liquid drying zone 13.

Recording heads (ink ejecting heads) 30K, 30C, 30M, 30Y, 30A, and 30B connected to ink storing portions for storing respective color inks of black (K), cyan (C), magenta (M), yellow (Y), special color ink (a), and special color ink (B) are disposed in the ink ejecting portion 14. Inks containing a colorant and water corresponding to the respective colors are stored in ink storage units, not shown, and are supplied to the ink discharge heads 30K, 30C, 30M, 30Y, 30A, and 30B as necessary when recording images.

Examples of the special color ink (a) and the special color ink (B) include white, orange, green, violet, light cyan, and light magenta inks.

In the image recording apparatus according to the present invention, which is suitable for the image recording method, the ink discharge heads 30A and 30B can be omitted. In addition, other heads for ejecting ink of special colors may be provided in addition to the heads 30A and 30B for ejecting ink.

In fig. 1, the positions of the ink discharge heads 30A and 30B in the transport direction of the polyester substrate are described on the downstream side of the yellow (Y) ink discharge head 30Y for convenience, but are not particularly limited as long as they are appropriately set in consideration of the lightness of the special color ink.

For example, a mode in which the ink discharge heads 30A and 30B are positioned between the yellow ink discharge head 30Y and the magenta ink discharge head 30M, a mode in which the magenta ink discharge head 30M and the cyan ink discharge head 30C are positioned, and the like can be considered.

The 30B is preferably a white ink discharge head.

The ink discharge heads 30K, 30C, 30M, 30Y, 30A, and 30B discharge the corresponding inks to the images from discharge nozzles disposed opposite to the image recording surface of the polyester base material. Thereby, each color ink was applied to the image recording surface of the polyester substrate to record a color image.

The ink discharge heads 30K, 30C, 30M, 30Y, 30A, and 30B are all in-line heads in which a plurality of discharge ports (nozzles) are arranged over the maximum recording width of an image recorded on the polyester substrate. This enables high-speed image recording on the polyester substrate, compared to a serial head that performs recording while reciprocally scanning a short reciprocal head in the width direction of the polyester substrate (the direction orthogonal to the conveying direction of the polyester substrate).

In the present invention, either serial recording or recording of a relatively high-speed recording system, for example, a single pass (single pass) system in which 1 line is formed by 1 scan, may be employed, and according to the image recording method of the present invention, a high-quality image with high reproducibility can be obtained even in a single pass system.

Here, the ink discharge heads 30K, 30C, 30M, 30Y, 30A, and 30B all have the same configuration.

The amount of the printing pretreatment liquid and the amount of the ink to be applied are preferably adjusted as necessary. For example, the amount of the printing pretreatment liquid to be added may be changed in order to adjust the physical properties such as viscoelasticity of an aggregate formed by mixing the printing pretreatment liquid and the ink according to the polyester substrate.

The ink drying zone 15 is disposed on the downstream side of the ink ejection section 14 in the polyester substrate conveyance direction.

The ink drying zone 15 can be configured similarly to the printing pretreatment liquid drying zone 13.

The image recording apparatus may further include a heating mechanism for performing a heat treatment on the polyester substrate on a transport path from the supply portion 11 to the accumulating portion 16.

For example, by disposing the heating means at a desired position on the upstream side of the printing pretreatment liquid drying zone 13, between the ink ejecting section 14 and the ink drying zone 15, or the like, the polyester substrate can be raised to a desired temperature, whereby drying of the printing pretreatment liquid, drying of the ink, fixing of the ink, and the like can be efficiently performed.

Further, since the image recording apparatus changes the surface temperature of the polyester substrate according to the type (material, thickness, etc.) of the polyester substrate, the environmental temperature, etc., it is preferable to include a heating control means including: a measuring section that measures a surface temperature of the polyester base material; a heating control unit for controlling heating conditions; and a control section that feeds back the value of the surface temperature of the polyester substrate measured at the measuring section to the heating control section.

The image recording apparatus is provided with a heating control means, and can supply ink or the like to the printing pretreatment liquid while controlling the temperature of the polyester substrate.

As a measuring portion for measuring the surface temperature of the polyester substrate, a contact or non-contact thermometer is preferable.