TWI754044B - Web Printing Ink, Gravure Web Printing Ink Set, Flexographic Web Printing Ink Set, Plastic Film Web Printing and Laminate - Google Patents

Abstract

The present invention is a rotary printing ink, which contains an aqueous urethane resin (A), a colorant, a hydrocarbon-based wax and water. In the rotary printing ink, the acid value of the aqueous urethane resin (A) is It is 25mgKOH/g~45mgKOH/g, and contains structural units represented by the following general formula (1) and general formula (2), the melting point of hydrocarbon wax is 90℃~140℃, and the average particle diameter is 0.5μm~ 10μm. In the general formula (1), Ph represents a substituted or unsubstituted phenyl group, in the general formula (2), R ¹ and R ² represent a substituted or unsubstituted aliphatic hydrocarbon group, which may be the same or different, A Represents an alicyclic hydrocarbon group.

Description

Web printing ink, gravure web printing ink set, flexo Web Printing Ink Sets, Plastic Film Web Printing and Laminates

Embodiments of the present invention relate to a web printing ink, web printing ink set, plastic film web printing and lamination.

In recent years, in the printing ink industry, there has been an increasing demand for water-based printing inks from the viewpoints of safety and hygiene during operation, environmental protection, and reduction of residual solvents in packaging materials. Therefore, a technique of using water-based polyurethane resin or polyurethane urea resin for aqueous ink has been proposed (Patent Document 1 to Patent Document 3).

On the other hand, rotary printing is printing with a reeling substrate, and compared with page printing in which printing is performed with a sheet of paper cut off one by one, printing can be performed continuously at a high speed, so it is suitable for a large number of copies. printing with good productivity. In rotary printing, it is important to prevent the adhesion of the printed matter printed at high speed (the accumulated printed matter is adhered to the non-printing surface of the substrate by applying winding pressure and the adhesiveness of the ink, etc., resulting in the phenomenon of reverse printing of the ink. ). In addition, the drying step is a method of passing the substrate through a drying oven while printing is performed, so it needs to be performed in a short time. Especially in the case of printing a plastic film, drying at high temperature must be avoided in view of the heat resistance of the film. , in the case of insufficient drying, resulting in residual moisture. solvent, so the dryness of the ink also becomes important.

[Prior Art Literature]

[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2008-49706

[Patent Document 2] Japanese Patent Laid-Open No. 2001-40057

[Patent Document 3] Japanese Patent Laid-Open No. 2005-272587

However, compared with solvent-based inks, conventional water-based inks have low water resistance and low adhesion to substrates, and therefore have a problem of low lamination strength when forming a layered laminate. In addition, improvement in blocking resistance (offset resistance) is also required.

An object of the embodiments of the present invention is to provide a web printing ink excellent in water resistance, lamination strength, and blocking resistance, and a web printing ink set, a plastic film printed matter, and a laminated laminate using the same.

One embodiment of the present invention relates to a web printing ink comprising an aqueous urethane resin (A), a colorant, a hydrocarbon-based wax and water, wherein the web printing ink contains an aqueous urethane resin (A) has an acid value of 25 mgKOH/g to 45 mgKOH/g, and contains structural units represented by the following general formulas (1) and (2), and the melting point of the hydrocarbon-based wax is 90° C. to 140° C., and the average The particle size is 0.5μm~10μm.

[Chemical 1] General formula (1) >N-Ph

(in the formula, Ph represents a substituted or unsubstituted phenyl group)

[Chemical 2] General formula (2) -R ¹ -AR ² -

(In the formula, R ¹ and R ² represent a substituted or unsubstituted aliphatic hydrocarbon group, which may be the same or different, and A represents an alicyclic hydrocarbon group)

Another embodiment is related to a gravure rotary printing ink set, which includes: a water-based urethane resin (A1), a water-based urethane resin (A2) and a white colorant for gravure printing. The rotary printing ink of one embodiment; and a colorant comprising an aqueous urethane resin (A1) and at least one color selected from the group consisting of cyan, magenta, yellow, and black and used for gravure printing One or more web printing inks of one embodiment.

Another embodiment relates to a flexographic rotary printing ink set comprising two or more of the rotary printing inks of one embodiment further comprising an aqueous urethane urea resin (B) and used for flexographic printing, The water-based urethane urea resin (B) comprises a branched polyester polyol unit, and the flexographic rotary printing ink set is a combination of the following flexographic rotary printing inks: A flexographic web printing ink containing a white colorant; and one or more flexographic web printing inks containing a colorant of at least one color selected from the group consisting of cyan, magenta, yellow, and black.

Another embodiment relates to a plastic film rotary printing, which has a printing layer on the surface of the plastic film, and the printing layer uses the rotary printing ink of the embodiment, the gravure rotary printing ink set of the embodiment, or the printing layer. It is formed by any one of the flexographic rotary printing ink sets of the above-mentioned embodiments.

Another embodiment relates to a manufacturing method of a plastic film rotary printing, which comprises using the rotary printing ink of the embodiment, the gravure rotary printing ink set of the embodiment, or the The flexographic web printing ink set of the embodiment is used for web printing.

Yet another embodiment relates to a laminated layered product comprising the plastic film web-printed product of the aforementioned embodiment.

According to the embodiment of the present invention, a web printing ink excellent in water resistance, lamination strength and blocking resistance can be provided.

Hereinafter, preferred embodiments of the present invention will be described, but the present invention is not limited to these embodiments. In addition, in this specification, mass and weight are used with the same meaning, therefore, it is unified as "weight" below.

One example of a preferred embodiment of the present invention is as follows (1) to (17).

(1) A rotary printing ink comprising an aqueous urethane resin (A), a colorant, a hydrocarbon-based wax and water, in which the acid value of the aqueous urethane resin (A) is It is 25mgKOH/g~45mgKOH/g, and contains structural units represented by the following general formula (1) and general formula (2), the melting point of hydrocarbon wax is 90℃~140℃, and the average particle diameter is 0.5μm~ 10μm.

[Chemical 3] General formula (1) >N-Ph

(in the formula, Ph represents a substituted or unsubstituted phenyl group)

[Chemical 4] General formula (2) -R ¹ -AR ² -

(In the formula, R ¹ and R ² represent a substituted or unsubstituted aliphatic hydrocarbon group, which may be the same or different, and A represents an alicyclic hydrocarbon group)

(2) The rotary printing ink according to (1) above, wherein the aqueous urethane resin (A) includes a structural unit of a compound having three or more functional groups reactive with isocyanate groups in the same molecule.

(3) The rotary printing ink according to (1) or (2), wherein the aqueous urethane resin (A) contains an aqueous urethane resin (A1) and an aqueous urethane resin ( At least one of A2), the aqueous urethane resin (A1) has 3% by weight to 7% by weight of polyethylene glycol units in the solid content of the aqueous urethane resin (A1), and the The aqueous urethane resin (A2) has a polyethylene glycol unit of 20% by weight to 30% by weight in the solid content of the aqueous urethane resin (A2).

(1') Use of an ink for rotary printing, the ink comprising an aqueous urethane resin (A), a colorant, a hydrocarbon-based wax and water, the aqueous urethane resin (A) The acid value is 25mgKOH/g~45mgKOH/g, and the structural unit represented by the general formula (1) and the general formula (2) is included, the melting point of the hydrocarbon wax is 90℃~140℃, and the average particle size is 0.5 μm~10μm.

(2') The use according to (1') above, wherein the aqueous urethane resin (A) contains a structural unit of a compound having three or more functional groups reactive with an isocyanate group in the same molecule.

(3') The use according to (1') or (2'), wherein the water-based urethane resin (A) contains the water-based urethane resin (A1) and the water-based urethane resin At least one of (A2).

(4) The web printing ink according to the above (3), which contains an aqueous urethane resin (A1), an aqueous urethane resin (A2), and a white colorant, and is used for gravure printing.

(5) The rotary printing ink according to the above (3) or (4), wherein, when both of the aqueous urethane resin (A1) and the aqueous urethane resin (A2) are contained, The solid content weight ratio of the aqueous urethane resin (A1) and the aqueous urethane resin (A2) is 30/70 to 50/50.

(6) The web printing ink according to (3), comprising an aqueous urethane resin (A1) and a colorant of at least one color selected from the group consisting of cyan, magenta, yellow, and black And for gravure printing.

(4') Use of a rotary printing ink for gravure printing, the rotary printing ink being the rotary printing ink of (3) and comprising an aqueous urethane resin (A1), an aqueous urethane resin Ester resin (A2) and white colorant.

(5') The use according to (4'), wherein the solid content weight ratio of the aqueous urethane resin (A1) and the aqueous urethane resin (A2) is 30/70 to 50/50 .

(6') Use of a rotary printing ink for gravure printing, the rotary printing ink being the rotary printing ink of (3) and comprising an aqueous urethane resin (A1) and a A colorant of at least one color from the group consisting of red, yellow, and black.

(7) The web printing ink according to any one of the above (1) to (3), which further contains an aqueous urethane urea resin (B), the aqueous urethane urea resin (B) Contains branched polyester polyol units.

(8) The rotary printing ink according to (7), wherein the solid content weight ratio of the aqueous urethane resin (A) to the aqueous urethane urea resin (B) is 25/75 to 45/ 55.

(9) The rotary printing ink according to (7) or (8), wherein the aqueous urethane resin (A) contains an aqueous urethane resin (A2), the aqueous urethane resin The resin (A2) has a polyethylene glycol unit of 20% by weight to 30% by weight in the solid content of the aqueous urethane resin (A2).

(10) The web printing ink according to any one of (7) to (9) above, which further contains a urethane/acrylic composite resin (C).

(11) The rotary printing ink according to (10), wherein the solid content weight ratio of the aqueous urethane resin (A) to the urethane/acrylic composite resin (C) is 85/15 to 99 /1.

(12) The web printing ink according to any one of (7) to (11) described above, which is used for flexographic printing.

(12') Use of a rotary printing ink for flexographic printing, wherein the rotary printing ink is the rotary printing ink of any one of (7) to (11).

(13) A gravure rotary printing ink set comprising the rotary printing ink as described in (4) and one or more of the rotary printing inks as described in (6).

(13') Use of a web printing ink set for gravure printing, the web printing ink set comprising the web printing ink as described in (4) and one or more web printing inks as described in (6) ink.

(14) A flexographic rotary printing ink set, comprising two or more rotary printing inks as described in (12), the flexographic rotary printing ink set is a combination of the following flexographic rotary printing inks: comprising white Flexographic web printing inks for colourants; and One or more flexographic web printing inks comprising colorants of at least one color selected from the group consisting of cyan, magenta, yellow, and black.

(14') Use of a rotary printing ink set for flexographic printing, the rotary printing ink set comprising two or more of the rotary printing inks of (12), and the rotary printing ink set is A combination of the following flexographic rotary printing inks: a flexographic rotary printing ink comprising a white colorant; and one or more flexographic printing inks comprising a colorant of at least one color selected from the group consisting of cyan, magenta, yellow, and black Rotary printing ink.

(15) A plastic film rotary printing, which has a printing layer on the surface of the plastic film, and the printing layer uses the rotary printing ink according to any one of (1) to (12), as described in (13) The gravure rotary printing ink set or the flexographic rotary printing ink set as described in (14) is formed.

(16) A manufacturing method of a plastic film rotary printing, which comprises using the rotary printing ink according to any one of the above (1) to (12), the gravure printing plate according to the above (13) on the surface of the rolled plastic film Web printing ink set or flexographic web printing ink set as described (14) for web printing.

(17) A laminated laminate comprising the plastic film web print as described in (15).

(15') A rotary printing ink according to any one of said (1) to (12), a gravure rotary printing ink set according to said (13), or a flexo rotary printing ink according to said (14) Use of any one of the kits for forming the print layer of a plastic film web print having a print layer on the surface of the plastic film.

(17') A rotary printing ink according to any one of (1) to (12), a gravure rotary printing ink set according to (13), or a flexographic rotary printing ink according to (14) Use of any one of the kits for a laminated laminate comprising the plastic film web print as described in (15), and for forming a print layer on the plastic film surface of the plastic film web print.

<Web Printing Ink>

The web printing ink contains at least an aqueous urethane resin (A), a colorant, a hydrocarbon-based wax, and water. This web printing ink can also form an excellent printed image by high-speed printing. In addition, various substrates can be selected as the type of substrate, and it is also suitable for non-permeable substrates other than ordinary printing paper. Printing on materials such as coated paper and plastic films (including plastic sheets).

Hereinafter, each component contained in the ink and the method for synthesizing the same, if necessary, will be described.

1. Water-based urethane resin (A)

Urethane is generally a resin obtained by reacting a polyisocyanate having two or more isocyanate groups in one molecule with a hydroxyl group-containing compound having two or more hydroxyl groups in one molecule. The aqueous urethane resin (A) of this embodiment has the following structure. As will be described later, such a configuration can be preferably introduced by appropriately selecting the structure, type, and the like of the hydroxyl group-containing compound.

The water-based urethane resin (A) does not contain a urea bond, and is different from the "urethane urea resin" described later in this respect.

The water-based urethane resin (A) has an acidic group (carboxyl group), and the acid value is relatively high. Preferably, it is 25mgKOH/g~45mgKOH/g. The acid value of the aqueous urethane resin (A) is 25 mgKOH/g or more, and by neutralizing the acidic functional group with an alkali, the dispersibility and solubility in water become sufficient and the storage stability of the ink can be obtained , and the pigment dispersibility and resolubility are also excellent. In addition, since the acid value of the aqueous urethane resin (A) is 45 mgKOH/g or less, the water resistance of the ink film when used as a binder can be ensured. The acid value is more preferably 40 mgKOH/g or less.

In order for the aqueous urethane resin (A) to have the acid value, it is preferable to use a compound containing a carboxyl group and a functional group (other than a carboxyl group) reactive with an isocyanate group as a synthesis raw material. As a functional group which can react with an isocyanate group, a hydroxyl group is preferable.

Examples of such a hydroxyl group-containing compound include 2,2-dimethylolpropionic acid, 2,2-dimethylolbutyric acid, 2,2-dimethylolbutyric acid, and 2,2-dimethylolbutyric acid. Dimethylolalkane acids such as valeric acid and the like can be used in combination of one or more of these. Among them, in terms of compatibility and reactivity with other urethane raw materials, 2,2-dimethylolpropionic acid and/or 2,2-dimethylolbutyric acid are preferably used. Here, since the isocyanate group preferentially reacts with the hydroxyl group of the carboxyl group-containing compound, most of the carboxyl groups remain in the side chain of the aqueous urethane resin (A) under mild reaction conditions of 60°C to 140°C.

The aqueous urethane resin (A) contains structural units represented by the following general formula (1) and general formula (2). By having these two structural units, the cohesion force of the ink film is improved, and the water resistance, blocking resistance and lamination strength of the ink film can be improved.

[Chem. 5] General formula (1) > N-Ph

(in the formula, Ph represents a substituted or unsubstituted phenyl group)

[Chemical 6] General formula (2) -R ¹ -AR ² -

(In the formula, R ¹ and R ² represent a substituted or unsubstituted aliphatic hydrocarbon group, which may be the same or different, and A represents an alicyclic hydrocarbon group)

Regarding the structural unit of the general formula (1), it is considered that the tertiary amine group and the carboxyl group form a quasi-crosslink in the coating film (film), and the blocking resistance and lamination strength of the coating film can be improved. better. A methyl group, an ethyl group, a propyl group, a methoxy group, an ethoxy group, etc. are mentioned as a substituent with respect to a phenyl group, You may have these two or more substituent groups. In addition, the substitution position with respect to the phenyl group may be any of the ortho position, the meta position, and the para position.

The structural unit of the general formula (1) can be preferably introduced by using, as a synthesis raw material, a compound containing the tertiary amine group of the general formula (1) and containing a functional group reactive with an isocyanate group. As a functional group which can react with an isocyanate group, a hydroxyl group, a carboxyl group, etc. are mentioned, From a viewpoint of reactivity with an isocyanate group, a hydroxyl group is preferable.

As a compound whose functional group which can react with an isocyanate group is a hydroxyl group, N,N-bis(2-hydroxypropyl)aniline having two hydroxyl groups, N,N-bis(2-hydroxyethyl) base) aniline, N,N-bis(2-hydroxyethyl)-3-chloroaniline, N,N-bis(2-hydroxyethyl)-p-toluidine, N,N-bis(2-hydroxyethyl) )-o-toluidine, N,N-bis(2-hydroxyethyl)-m-toluidine, N,N-bis(2-hydroxyethyl)-m-xylidine and N,N-bis(2-hydroxyl) ethyl)-p-xylidine etc. As the compound having one hydroxyl group, N-hydroxyethylaniline, N-(2-cyanoethyl)-N-(2-hydroxyethyl)aniline, and 2-hydroxyethylaniline are exemplified (N-ethylaniline) ethanol or the like can be used alone or in combination of two or more. From the viewpoints of the stability of the aqueous resin, the adhesiveness to a plastic film, and the like, N,N-bis(2-hydroxypropyl)aniline is preferred.

As a compound whose functional group which can react with an isocyanate group is a carboxyl group, N,N-bis(2-carboxyethyl)aniline etc. can be mentioned, and these can be used in combination of 1 type or 2 or more types.

The structural unit of the general formula (2) is preferable in that the water resistance and blocking resistance of the coating film can be improved. This structural unit can be preferably introduced by using, as a synthesis raw material, a compound containing the structural unit of the general formula (2) and containing a functional group reactive with an isocyanate group. The raw material having the structural unit of the general formula (2) is reacted with an isocyanate compound to impart rigidity of the structure due to the alicyclic hydrocarbon group to the molecule of the aqueous urethane resin (A), and in addition, a large number of amino groups are added. The formate bond is introduced into the molecule and the coating film is formed firmly, and it is also considered that it contributes to the improvement of water resistance and blocking resistance in this respect.

In the general formula (2), R ¹ and R ² represent a substituted or unsubstituted divalent aliphatic hydrocarbon group, which may be the same or different from each other. That is, R ¹ and R ² are divalent hydrocarbon groups that do not have aromaticity and include carbon and hydrogen excluding substituents, and may have an unsaturated bond. The carbon number of the aliphatic hydrocarbon group (excluding the carbon number contained in the substituent) is preferably 1-5, more preferably 1-3. As a substituent in the case of having a substituent, an alkyl group, an unsaturated bond group, etc. are mentioned. Specific examples of R ¹ and R ² include a methylene group, an ethylidene group, a propylidene group, and the like.

In the general formula (2), A represents a divalent alicyclic hydrocarbon group. That is, A is a monocyclic or polycyclic group which does not have aromaticity and contains carbon and hydrogen, and may have an unsaturated bond. The number of ring members of the alicyclic hydrocarbon group is preferably 5 to 10, particularly preferably a 6-membered ring. As A, a cyclopentane ring, a cyclohexane ring, a cyclodecane ring, etc. can be illustrated specifically,. A is preferably a cyclohexylene group and a bicyclohexylene group, and examples thereof include a cyclohexylene group and a methylene bicyclohexylene group, and may be a mixture of structural isomers.

Furthermore, as a raw material compound which can introduce the structural unit of General formula (2) in detail, 1, 4- cyclohexane dimethanol, 1, 1- cyclohexane diethanol, etc. are mentioned. Two or more of these can also be used.

In the aqueous urethane resin (A), as the structural unit of the general formula (1), it is preferable to include a structure derived from N,N-bis(2-hydroxypropyl)aniline, as the structural unit of the general formula (1). The structural unit of the general formula (2) preferably contains a structure derived from 1,4-cyclohexanedimethanol.

In addition, in the aqueous urethane resin (A), it is not particularly limited, and the structural unit of the general formula (1) is preferably contained in 5% by weight to 10% by weight in the solid content of the resin, and the general formula The structural unit of the formula (2) is preferably contained in the resin solid content in an amount of 0.5% by weight to 5% by weight. This ratio can be determined by the total weight of all the raw materials used in the synthesis of the aqueous urethane resin (A) and the amount of each component for introducing each structural unit. Calculated based on the weight of the raw material.

In one embodiment, the aqueous urethane resin (A) preferably contains a structural unit derived from a compound having three or more functional groups reactive with an isocyanate group in the same molecule. By using this compound, three-dimensional crosslinking can be achieved in the urethane resin, the ink film (coating film) becomes firm, and the blocking resistance, lamination strength and cohesion of the ink film can be further improved. Wait. The water-based urethane (A) of this embodiment preferably contains 0.05 wt % or more of the solid content of the water-based urethane resin (A) based on the total solid content of the water-based urethane resin (A). The structural unit of the compound of the isocyanate group-reacted functional group is more preferably 0.1% by weight or more, and preferably 0.8% by weight or less, more preferably 0.6% by weight or less, and more specifically, preferably It is contained in the range of 0.05 to 0.8 weight %, and it is more preferable to be contained in the range of 0.1 to 0.6 weight %.

Among compounds having three or more functional groups reactive with isocyanate groups in the same molecule, as described above, functional groups reactive with isocyanate groups include hydroxyl groups and carboxyl groups. In terms of the bonding group, a hydroxyl group is preferred.

As a compound which has three or more hydroxyl groups, trimethylolethane, trimethylolpropane, 1, 2, 6- hexanetriol, pentaerythritol, etc. are mentioned. It is preferable to use the polyol which has these three or more hydroxyl groups as needed in the range which does not gel urethane resin. Trimethylolpropane is preferred.

Moreover, as a compound which can introduce|transduce this structural unit, it is also preferable to use the compound which has a total of three or more hydroxyl groups and carboxyl groups. For example, dimethylol Dimethylolalkanoic acids such as methylolpropionic acid, 2,2-dimethylolacetic acid, 2,2-dimethylolbutyric acid, 2,2-dimethylolvaleric acid, and dihydroxypropionic acid; dihydroxybutane Diacid and dihydroxybenzoic acid. Among these compounds, since the hydroxyl group preferentially reacts with the isocyanate group, the carboxyl group can be introduced into the urethane resin, and the water-based resin can be easily achieved by neutralizing the carboxylic acid with ammonia or an alkali. In particular, in terms of reactivity and solubility, dimethylolpropionic acid and 2,2-dimethylolbutyric acid are preferably used.

As the hydroxyl group-containing compound for synthesizing the aqueous urethane resin (A), it is preferable to use the above-mentioned compound, but it is also preferable to use a general polyol not having a specific structure in combination. For example, a low molecular weight diol and a high molecular weight diol having two hydroxyl groups in one molecule can be used.

Specifically, as a low molecular weight glycol, diethylene glycol, trimethylene glycol, triethylene glycol, propylene glycol, butanediol, hexamethylene glycol, neopentyl glycol, etc. can be mentioned, and may also be used. two or more of these.

As a high molecular weight diol, a polyether system, a polyester system, an epoxy system, etc. are mentioned. Among them, polyether-based and/or polyester-based high-molecular-weight diols are preferably used. As a polyether system, polyethylene glycol, polyoxypropylene glycol, poly(ethylene/propylene) glycol, polytetramethylene glycol, etc. are mentioned. Polyester-based diols are obtained by polycondensation of diols and dibasic acids. As the raw material diol, ethylene glycol, diethylene glycol, dipropylene glycol, 1,4-butanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 2- Methyl-1, 3- propanediol, neopentyl glycol, etc., as a raw material dibasic acid, adipic acid, azelaic acid, sebacic acid, isophthalic acid, terephthalic acid, etc. are mentioned. In one embodiment, it is preferable to use a compound having a compound derived from the group consisting of 3-methyl-1,5-pentanediol, 2-methyl-1,3-propanediol, and neopentyl glycol. A polyester-based diol having a structure of one or more compounds in the group. Moreover, as a high molecular weight body which has two hydroxyl groups, lactone ring-opening polymers, polycarbonate, etc., such as polycaprolactone and poly (beta)-methyl- (delta)-valerolactone, are mentioned.

The hydroxyl-containing compounds described above are preferably used alone or in combination of two or more. In order to obtain a balance between the adhesion to the film substrate, the film properties of the ink, and the water resistance, it is preferable to use two or more kinds of different chemical structures together, or to appropriately select the molecular weights of these.

As described above, in one embodiment, it is preferable that the water-based urethane resin (A) contains a structural unit of a polyether-based and/or polyester-based high-molecular-weight diol and has three or more in the same molecule. A structural unit of a compound of a functional group reactive with an isocyanate group. In addition, in another embodiment, it is preferable that the water-based urethane resin (A) contains a structural unit of a polyether-based and/or polyester-based high-molecular-weight diol, and has three or more possible diols in the same molecule. The structural unit of the compound of the functional group reacted with the isocyanate group, and the structural unit of the general formula (1) contains 5% by weight to 10% by weight in the solid content of the resin, and the structural unit of the general formula (2) is contained in the resin. The solid content contains 0.5% by weight to 5% by weight.

In one embodiment, in the production of the aqueous urethane resin, it is preferable to use polyethylene glycol (hereinafter, also abbreviated as "PEG") as the hydroxyl group-containing compound, so that water solubility can be easily achieved, and the obtained Stable dispersion, hydrosol or water soluble resin. In addition, by using PEG in the production of aqueous urethane resin at a specific weight ratio, moderate viscosity as ink can be imparted, and printability such as transferability to a substrate can be improved during printing. .

Therefore, the water-based urethane resin (A) preferably contains a structural unit of a polyether-based high-molecular-weight diol, and contains the water-based urethane resin (A1) and the water-based urethane resin (A2) At least one of the water-based urethane resin (A1) has 3% by weight to 7% by weight of PEG units in the solid content of the water-based urethane resin (A1), and the water-based urethane resin (A1) The acid ester resin (A2) has a PEG unit of 20% by weight to 30% by weight in the solid content of the aqueous urethane resin (A2). By using the resin (A1) with a small number of PEG units, the above-described properties of the PEG units can be exerted, and the water resistance of the film can be improved. By using the resin (A2) with many PEG units, the above-described properties of the PEG units can be exerted, and the pigment dispersibility and color development can be improved. Moreover, by combining resin (A1) and resin (A2), the adhesiveness of a film with respect to a to-be-printed body can be improved. Therefore, the resin (A1) and the resin (A2) can be selected according to the application of the ink.

For example, in gravure printing, printing ink is supplied to a gravure cylinder with grooves formed on the surface, and the excess printing ink on the surface of the cylinder is scraped off with a doctor blade, and then the to-be-printed body is printed on the gravure cylinder for gravure printing. In the case of web printing ink, the transferability of the ink in the tank to the printed body and the resolubility of the ink remaining in the tank are required, so the dispersibility of colorants (especially pigments) and the stability of dispersion, etc. become important. By using the aqueous urethane resin (A1), the dispersibility of the pigment is improved, and when a printed matter is formed, a coating film excellent in cohesion can be obtained.

In addition, with regard to white ink, titanium oxide is generally used as a pigment, and as a result, it is difficult to disperse due to the large specific gravity of titanium oxide. In addition, white pigments for maintaining tinting strength The content of ink is more than that of color inks other than white. Therefore, in the case of the white ink for gravure printing, it is preferable to combine the aqueous urethane resin (A1) and the aqueous urethane resin (A2). Furthermore, it is more preferable to use the aqueous urethane resin (A2) for the dispersion to improve the dispersibility of the pigment, and thereafter, the aqueous urethane resin (A1) is added and mixed. By using them together, the resolubility of the ink component is also improved, so that the accumulation of the white pigment in the concave portion of the gravure can be prevented or reduced. The solid content weight ratio of the aqueous urethane resin (A1) and the aqueous urethane resin (A2) when used together is preferably 30/70 to 50/50.

That is, in one embodiment, the rotary printing ink is a gravure rotary printing white ink containing an aqueous urethane resin (A1), an aqueous urethane resin (A2), a white colorant, a hydrocarbon-based wax, and water . By including the water-based urethane resin (A2), there is also a reduction in plate whitening (in gravure printing, the ink cannot be cut with a doctor blade and the ink is transferred to parts other than the image area) Effect.

In another embodiment, the rotary printing ink is a gravure rotary printing color ink containing an aqueous urethane resin (A1), a colorant other than white, a hydrocarbon-based wax, and water. In the case of this gravure rotary printing color ink, sufficient pigment dispersibility and resolubility can be obtained only by the aqueous urethane resin (A1). The water-based urethane resin (A2) may also be included. If the water-based urethane resin (A1) is the main resin, the amount of PEG will be small, so the water resistance of the printed layer will be good, and the blocking resistance will be improved. (offset resistance) became better.

In this specification, the ink containing a white colorant is described as "white ink", the colorant other than white is described as "color colorant", and the colorant other than white is described as "color colorant". The ink is recorded as "color ink".

The color colorant preferably contains at least one color selected from the group consisting of cyan, magenta, yellow, and black, or any one of these colors, but is not particularly limited thereto, and may also be a so-called "special color" ”, that is, other colors other than the basic colors of CMYK, etc.

Next, aromatic, aliphatic, alicyclic difunctional isocyanate, trifunctional isocyanate, etc. are mentioned as polyisocyanate which reacts with a hydroxyl-containing compound. Among them, difunctional isocyanates are preferred, and examples of the difunctional isocyanates include 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, isophenylene diisocyanate, p-phenylene diisocyanate, 4,4'- Diphenylmethane diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, xylene diisocyanate, isophorone diisocyanate, trimethylhexamethylene diisocyanate, 1,4-cyclohexylene Diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 3,3'-dimethyl-4,4'-biphenylene diisocyanate, 3,3'-dimethoxy-4,4'- Biphenylene diisocyanate, 3,3'-dichloro-4,4'-biphenylene diisocyanate, 1,5-naphthalene diisocyanate, 1,5-tetrahydronaphthalene diisocyanate, 2,5(2,6 )-bicyclo[2.2.1]heptanebis(isocyanatomethyl)(norbornane diisocyanate) and the like, and these may be used alone or in combination of two or more.

Examples of trifunctional isocyanates include: 1) adducts of trimethylolpropane, such as Takenate D-160N (manufactured by Takeda Pharmaceutical Co., Ltd.) and Sumidule HT (Sumitomo Corporation) Bayer Urethane (manufactured by Co., Ltd.); 2) Biuret compounds such as Takenate D-165N (manufactured by Takeda Pharmaceutical Co., Ltd.) and Sumidule N3200 (Sumitomo Co., Ltd.) 3) Isocyanurate ring type, for example, VESTANAT T1890 (manufactured by HULS (stock)) and the like. When a trifunctional isocyanate is used, from the viewpoints of improvement of cohesion force, viscosity control during reaction, etc., 0.05% by weight to 2% by weight of the solid content of the aqueous urethane resin (A) is particularly preferred. .

The reaction molar ratio (NCO/OH) of the isocyanate group and the hydroxyl group of the aqueous urethane resin (A) is not particularly limited, but from the viewpoints of the molecular weight of the resin and the control of the number of urethane bonds, etc. It is preferably 0.9 or more, more preferably 0.94 or more, and more preferably 0.99 or less, more preferably 0.98 or less, more specifically, 0.9 to 0.99, more preferably 0.94 to 0.98.

Next, the synthesis method of the aqueous urethane resin (A) is demonstrated. The aqueous urethane resin (A) can be obtained by an acetone method using an organic solvent, a solvent-free synthesis method using no solvent at all, and the like, and its production method is not particularly limited. In the latter case, the viscosity usually becomes high, and therefore it is necessary to pay attention to the stirring device, the composition of the raw materials, and the method of chain extension. Hereinafter, the acetone method and the solvent-free synthesis method will be described, respectively.

The acetone method refers to a method in which ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone are used in reactions in which the viscosity becomes extremely high or in reactions that tend to become non-uniform, such as partial gelation. based solvents; ester based solvents such as ethyl acetate and butyl acetate; and aromatic organic solvents such as toluene and xylene. When an organic solvent is used, the viscosity of the reaction system is reduced, and the synthesis reaction can be performed uniformly and smoothly.

It is preferable to use a catalyst for the reaction of a polyisocyanate and a hydroxyl-containing compound. As the catalyst, a known metal-based catalyst or amine-based catalyst can be used. as metal Catalysts include: dibutyltin dilaurate, tin octoate, dibutyltin bis(2-ethylhexanoate), lead 2-ethylhexanoate, 2-ethylhexyl titanate, 2-ethylhexanoate Iron hexanoate, cobalt 2-ethylhexanoate, zinc naphthenate, cobalt naphthenate and tetra-n-butyl tin, etc. As an amine catalyst, tertiary amines, such as tetramethylbutanediamine, etc. are mentioned.

The urethane reaction is preferably carried out at 50°C to 100°C for 10 minutes to 10 hours. The end point of the reaction can be judged by viscosity measurement, NCO peak value obtained by infrared (IR) measurement, NCO% measurement obtained by titration, or the like.

After obtaining a urethane resin having a predetermined molecular weight, it is preferable to neutralize the carboxyl group in the resin with a basic compound in order to make it water-based. Examples of basic compounds include: Inorganic hydroxides such as sodium hydroxide and potassium hydroxide; ammonia, methylamine, ethylamine, propylamine, butylamine, hexylamine, octylamine, ethanolamine, propanolamine, diethanolamine, N-methylamine diethanolamine, dimethylamine, diethylamine, triethylamine, N,N-dimethylethanolamine, 2-dimethylamino-2-methyl-1-propanol, 2-amino -Amine compounds such as 2-methyl-1-propanol and morpholine, and these can be used alone or in combination of two or more. Depending on the type of the basic compound, the ease of permeation with respect to the polyurethane solution and the stability after aqueous conversion may be different, so it is necessary to select it appropriately. Among these, amine compounds are preferred, and ammonia is preferred from the viewpoints of water resistance and residual odor of printed matter.

In neutralization of the compound which has a carboxyl group, such as dimethylol alkane acid, it is preferable to use 0.4-1.2 equivalents of a basic compound with respect to 1 equivalent of a carboxyl group. The method for water-based urethane resin is as follows: using the carboxyl group-containing dibasic A method of neutralizing an alcohol with an alkali, a method of using polyethylene glycol with high water solubility, and the like. In particular, when both are used together, a resin having a balance between stability as a water-soluble resin and water resistance as an ink can be obtained.

In the acetone method, desolvation is required depending on the type and amount of the solvent used. Desolvation can be carried out, for example, by adding water and a basic compound as a neutralizing agent to the reaction solution, then raising the temperature and distilling off a necessary amount of the solvent under normal pressure or reduced pressure.

In the solvent-free synthesis method, the polyol and the isocyanate may be initially charged, or the isocyanate may be added after the polyol is charged. In the synthesis reaction, since the viscosity usually becomes a problem, it is preferable to raise the temperature to such an extent that sufficient stirring is possible to reduce the viscosity. Preferably, the resin raw material is sufficiently dissolved or melted to start the reaction in a uniform state. When the reaction initiation temperature is low or the compatibility between the resin raw materials or between the raw materials and the resulting resin is insufficient, a part of the raw materials are dispersed in the molten raw material, and the appearance becomes slightly opaque. It can be produced even in this state. For example, in the case of a polyol containing polyethylene glycol, if the reaction temperature is set to be higher than the compatibility temperature, even diols with poor compatibility can be obtained. Homogeneous resin.

The urethane reaction is preferably carried out at 90°C to 200°C for 10 minutes to 5 hours. The end point of the reaction can be judged by viscosity measurement, NCO peak value obtained by IR measurement, or NCO% measurement obtained by titration.

The water-based urethane resin can be carried out by neutralization with the carboxyl group of the basic compound, or by water-solubilization with polyethylene glycol or the like. When the reaction is carried out without a solvent, even if only water and a basic compound are used, water-based conversion can be achieved. However, since the organic solvent has the function of temporarily making the high-viscosity reactant into a resin solution and making it water-based smoothly, if the organic solvent is used as an auxiliary before the water-based urethane resin, it is easy to water-based. In this case, it may be added directly after the completion of the synthesis of the urethane resin, or conversely, the urethane resin may be added and dissolved in an organic solvent.

When an alcohol is used as an organic solvent, since alcohol is often used together with an aqueous printing ink, there is an advantage that it can be used as it is without desolventizing. Examples of the alcohol include polyhydric alcohols such as monohydric alcohols and diols, and glycol ethers. Furthermore, in detail, for example, methanol, ethanol, n-propanol, isopropanol, n-butanol, tert-butanol, ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol can be mentioned. Monoisopropyl ether, ethylene glycol mono-n-butyl ether, ethylene glycol monoisobutyl ether, ethylene glycol mono-n-hexyl ether, diethylene glycol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethyl ether Glycol monobutyl ether, diethylene glycol monoisobutyl ether, diethylene glycol mono-n-hexyl ether and 2,2,4-trimethylpentanediol-1,3-monoisobutyrate (Tesanolu (TEXANOL), manufactured by Eastman Chemical (Eastman Chemical), etc., especially preferred are isopropanol, n-propanol, n-butanol, ethanol and methanol. These may be used alone or in combination of two or more. The desolvation process can also be omitted by appropriately selecting an alcohol suitable for the printing viscosity (diluting property), drying property, and film-forming property of the target printing ink from these alcohols.

The solvent-free synthesis method, which is a second method for obtaining an aqueous urethane resin, can eliminate the cost and the like due to the use of a solvent, and therefore has great advantages in terms of productivity and cost. In particular, when the residual solvent amount of the printed matter becomes a problem, the proportion of the desolvation step in all the production steps increases, and it becomes a problem to improve the water solubility. A major factor in the production cost of urethane resins.

The number of urethane bonds (mmol/g) of the aqueous urethane resin (A) is not particularly limited, but is preferably 2.2 mmol from the viewpoints of the molecular weight of the resin and the adjustment of the hardness of the coating film. /g or more, more preferably 2.3 mmol/g or more, and more preferably 3.0 mmol/g or less, more preferably 2.9 mmol/g or less. More specifically, the number of urethane bonds is preferably 2.2 mmol/g to 3.0 mmol/g, more preferably 2.3 mmol/g to 2.9 mmol/g. The number of urethane bonds can be adjusted to a desired range by appropriately adjusting the amounts and reaction conditions of the hydroxyl group-containing compound and polyisocyanate.

The glass transition temperature (Tg) of the water-based urethane resin (A) and the later-described water-based urethane urea resin (B) is not particularly limited, but is preferably a water-based urethane resin (A) The temperature is -70°C or lower, and the water-based urethane urea resin (B) is -50°C or lower. In the water-based urethane resin (A), the Tg of the water-based urethane resin (A1) is preferably -70°C or lower, more preferably -70°C to -90°C, and the water-based urethane resin The Tg of the resin (A2) is preferably -90°C or lower. When the Tg of the aqueous urethane resin (A) is -70° C. or lower, the film-forming properties of the ink are improved, and the adhesion of the coating film is improved. As for the water-based urethane urea resin (B), by using a Tg of -50°C or less, preferably -50°C to -70°C in combination with the water-based urethane resin (A), after printing The washability of the plate is improved, so it is better. The Tg of the aqueous urethane resin (A) and the aqueous urethane urea resin (B) can be measured by a scanning differential thermal analysis method at a temperature increase rate of 10° C./min.

The weight average molecular weight of the aqueous urethane resin (A) (Gel Permeation Chromatography, GPC), standard polyphenylene ethylene conversion) is not particularly limited, but is preferably 10,000 or more, more preferably 30,000 or more, and more preferably 100,000 or less, more preferably 70,000 or less. More specifically, the weight average molecular weight is preferably 10,000 to 100,000, more preferably 30,000 to 70,000.

The hydroxyl value (mgKOH/g) of the aqueous urethane resin (A) is not particularly limited, but from the viewpoint of water resistance and the like, it is preferably 0.0 mgKOH/g to 3.0 mgKOH/g, more preferably 0.0 mgKOH /g~2.0mgKOH/g.

The aqueous urethane resin (A) is preferably contained in the total amount of the rotary printing ink in an amount of 3% by weight or more, more preferably 5% by weight or more, and particularly preferably 7% by weight or more. On the other hand, the content of the aqueous urethane resin (A) is preferably 25 wt % or less, more preferably 20 wt % or less, and particularly preferably 17 wt % or less in the total amount of the rotary printing ink.

2. Water-based urethane urea resin (B)

The water-based urethane resin (A) does not contain a urea bond. In one embodiment, the web printing ink may further comprise a water-based urethane urea resin (B) containing a urea bond.

In particular, the aqueous urethane urea resin (B) preferably contains a branched polyester polyol unit from the viewpoints of printability and plate washability in flexographic printing. Here, the branch is an alkyl group, and the polyol having a branch means a structure in which at least one of the hydrogen atoms on the alkylene group contained in the polyol is substituted with an alkyl group.

The branched polyester polyol unit can preferably be introduced by combining neopentyl glycol, 1,2-propanediol, 2-ethyl-2-butyl-propanediol, 2-methyl-1 ,3- Polyester polyols synthesized from branched polyols such as propylene glycol and 3-methyl-1,5-pentanediol and polyvalent carboxylic acids are used as raw materials for the synthesis of urethane urea resins.

A urea bond can be suitably introduce|transduced by carrying out the chain extension reaction using arbitrary diamines. Examples of the chain extender include aliphatic diamines such as ethylenediamine, hexamethylenediamine, and 2,2,4-trimethylhexamethylenediamine; isophoronediamine and 1,4 - Alicyclic diamines such as diaminocyclohexane; dihydrazine malonate, dihydrazine succinate, dihydrazine glutarate, dihydrazine adipic acid and dihydrazine sebacate Hydrazine compounds, etc. In addition, 2-hydroxyethylethylenediamine, 2-hydroxyethylpropylenediamine, di-2-hydroxyethylethylenediamine, di-2-hydroxyethylpropylenediamine, 2-hydroxypropyl Diamines having a hydroxyl group such as ethylenediamine and di-2-hydroxypropylethylenediamine. By using a diamine having a hydroxyl group, a hydroxyl group can be introduced into the water-based urethane urea resin (B), and there is an advantage in that when a hardener that can react with a hydroxyl group is used, the coating film can be improved. Crosslink density and improve blocking resistance and water resistance. One or two or more of these can be used. Moreover, polyamines, such as diethylenetriamine and triethylenetetramine, can also be used in the range which does not gel urethane resin.

Among them, isophoronediamine and 2-hydroxyethylethylenediamine (2-aminoethylethanolamine) are preferably used.

A reaction terminator can also be used in the chain extension reaction. As the reaction terminator, for example, in addition to dialkylamines such as di-n-butylamine, monoethanolamine, diethanolamine, 2-amino-2-methyl-1-propanol, tris(hydroxymethyl) amines having hydroxyl groups such as aminomethane and 2-amino-2-ethyl-1,3-propanediol. By using a reaction terminator and a chain extender in combination, the molecular weight can be easily controlled, and the functional group at the terminal can be import.

The chain extension reaction is preferably carried out at 30°C to 80°C for 10 minutes to 10 hours. The end point of the reaction can be judged by viscosity measurement, NCO peak obtained by IR measurement, or amine value measurement by titration, or the like.

The molar ratio (NCO/OH) of the reaction between the isocyanate group and the hydroxyl group of the water-based urethane urea resin (B) is not particularly limited, and it is the balance between the softness and hardness of the resin caused by the urethane bond concentration. , From the viewpoints of blocking resistance when forming a coating film, substrate adhesion in flexible packaging applications, and substrate followability, etc., preferably 1.2 or more, more preferably 1.5 or more, and preferably 2.5 or less , more preferably 1.8 or less, more specifically, preferably 1.2 to 2.5, more preferably 1.5 to 1.8. By setting the reaction molar ratio of the two to, for example, 1.2 to 2.5, a urethane prepolymer having an isocyanate group at the terminal can be preferably obtained.

The urethane prepolymer which has an isocyanate group at a terminal becomes a urethane urea resin (B) by chain extension with the chain extension agent which has an amine group. The molar ratio (NH/residual NCO) of the reaction between the amine group of the chain extender and the isocyanate group (residual NCO) of the urethane prepolymer is not particularly limited, and the molecular weight, the control of the terminal group and the urea bond concentration, etc. are not particularly limited. From the viewpoint of , preferably 0.8 or more, more preferably 0.9 or more, and more preferably 1.2 or less, more preferably 1.1 or less, more specifically, 0.8 to 1.2, more preferably 0.9 to 1.1. Furthermore, the isocyanate group related to the urea bond is the residual isocyanate group (residual NCO) after the formation of the urethane bond.

The weight-average molecular weight (measured by GPC, in terms of standard polystyrene) of the water-based urethane urea resin (B) is not particularly limited, and the resolubility and blocking resistance are not particularly limited. From the viewpoint of properties and the like, it is preferably 10,000 or more, more preferably 30,000 or more, and more preferably 100,000 or less, more preferably 70,000 or less. More specifically, it is preferably 10,000 to 100,000, and more preferably 30,000 to 70,000.

The acid value (mgKOH/g) of the aqueous urethane urea resin (B) is not particularly limited, but from the viewpoints of resolubility and water resistance, it is preferably 25 mgKOH/g or more, more preferably 30 mgKOH/g. g or more, and preferably 45 mgKOH/g or less, more preferably 40 mgKOH/g or less, more specifically, preferably 25 mgKOH/g to 45 mgKOH/g, more preferably 30 mgKOH/g to 40 mgKOH/g. The acid value is a value obtained by converting the acid amount in 1 g of resin calculated by titrating acid with an alkali to mg of potassium hydroxide, and is a measured value based on Japanese Industrial Standards (JIS) K0070:1992.

The aqueous urethane urea resin (B) preferably has a hydroxyl value (mgKOH/g). The hydroxyl value of the water-based urethane urea resin (B) is not particularly limited, but is preferably 35 mgKOH/g or less from the viewpoints of water resistance, blocking resistance, introduction of a crosslinked structure into a coating film, and the like , more preferably 25 mgKOH/g or less, and more preferably 1 mgKOH/g or more, still more preferably 5 mgKOH/g or more. More specifically, the hydroxyl value is preferably 0mgKOH/g~35mgKOH/g, more preferably 0mgKOH/g~25mgKOH/g, more preferably 1mgKOH/g~35mgKOH/g, and still more preferably 5mgKOH/g ~25mgKOH/g. The hydroxyl value is a value obtained by converting the amount of hydroxyl groups in 1 g of resin calculated by esterifying or acetylating the hydroxyl groups in the resin and back titrating the remaining acid with an alkali to the number of mg of potassium hydroxide, and is based on Measured value of JIS K0070:1992.

When a large number of amine groups are present in the water-based polyurethane urea resin (B), there are carboxyl groups and salt structures that are easy to obtain the water-based urethane urea resin, and the time-dependent stability and pigment dispersibility of the ink decrease Case. Moreover, when there are many amino groups, when using an isocyanate type hardening|curing agent, the tendency for the time-dependent stability of an ink to fall is observed. On the other hand, the adhesiveness to a base material, especially the adhesiveness and blocking resistance to a polyolefin film improves by presence of an amine group. Therefore, the amine value of the water-based polyurethane urea resin (B) is preferably in the range of 0 mgKOH/g to 13 mgKOH/g. More preferably, it is 0 mgKOH/g to 10 mgKOH/g. The amine group in the aqueous urethane urea resin (B) can be introduced into a side chain and/or a terminal.

The amine value can be measured by a known titration method in accordance with JIS K0070:1992. That is, a sample of 0.5 g to 2 g is accurately weighed (sample amount: S g, solid content: Z%), and 30 mL of neutral ethanol (BDG neutral) is added and dissolved in the precisely weighed sample. The obtained solution was titrated with a 0.2 mol/L ethanolic hydrochloric acid solution (titer: f). The point at which the color of the solution changed from green to yellow was set as the end point, and the amine valence was determined by the following (Formula 1) using the titration amount (A mL) at that time.

(Formula 1) Amine valence=(A×f×0.2×56.108)/(S×Z/100)

The water-based urethane urea resin (B) is preferable in that the adhesiveness of the ink film to the printed body can be further improved. In the case where the web printing ink contains the aqueous urethane urea resin (B), the aqueous urethane resin (A) The solid content weight ratio with the aqueous urethane urea resin (B) is preferably 25/75 or more, and also preferably 45/55 or less, more specifically, 25/75 to 45/55.

On the other hand, the preparation of the aqueous urethane urea resin (B) leads to an increase in the production cost of the ink, and further, according to the study by the present inventors, in gravure printing, the printability of the resin (B) is not included. Excellent.

Therefore, in the case of the flexographic rotary printing ink for flexographic printing, it is preferable to contain the aqueous urethane urea resin (B). In addition, when used for flexographic printing, the aqueous urethane resin (A) of the web printing ink preferably contains an aqueous urethane having a large PEG content from the viewpoint of plate washability and the like Resin (A2). Furthermore, it is also especially preferable to contain the urethane/acrylic composite resin (C) mentioned later.

That is, in one embodiment, the rotary printing ink is a flexographic rotary printing containing an aqueous urethane resin (A2), an aqueous urethane urea resin (B), a white colorant, a hydrocarbon-based wax, and water White ink.

In another embodiment, the web printing ink is a flexographic plate containing an aqueous urethane resin (A2), an aqueous urethane urea resin (B), a colorant other than white, a hydrocarbon-based wax, and water Web printing color ink.

3. Urethane/acrylic composite resin (C)

The web printing ink may further comprise the urethane/acrylic composite resin (C). By including the urethane/acrylic composite resin (C), especially, in a flexographic ink, an advantage of improved washability can be obtained.

The urethane/acrylic composite resin (C) is a composite resin composed of a urethane component and an acrylic component as essential constituent components. Urethane/ Although the urethane component of an acrylic composite resin is not specifically limited, For example, it consists of a polyisocyanate compound and a polyol compound as raw material components. As the polyisocyanate compound, for example, one compound or a mixture of two or more kinds selected from known diisocyanates such as aromatic diisocyanate, aliphatic diisocyanate, and alicyclic diisocyanate can be used. By combining these polyisocyanate compounds with, as polyol compounds, low molecular weight diols, polyether diols, polyester diols; or polycaprolactone diols, polyvalerolactone diols, lactone blocks A urethane component is obtained by reacting well-known diols, such as a lactone diol, such as a copolymerized diol. Moreover, as a polyol compound, an acrylic polyol can also be used.

Examples of the monomer component constituting the acrylic component of the urethane/acrylic composite resin (C) include (meth)acrylic acid alkyl ester having a linear or branched alkyl group, a carboxyl group-containing ( Meth)acrylic acid, hydroxyl-containing (meth)acrylates, (meth)acrylate amide derivatives, and (meth)acrylate dialkylamino alkyl esters, preferably one or more of these In addition to the acrylic monomer, a polymerizable unsaturated compound such as a styrene compound, a vinyl ester, and a cyano group-containing vinyl compound may be used in combination.

The water-based urethane/acrylic composite resin (C) can be achieved by using water-based components in the urethane component and/or the acrylic component, for example, in the urethane component and/or the acrylic component. As the component, dimethylolpropionic acid, dimethylolbutyric acid, or the like is used, and as the acrylic component, (meth)acrylic acid, itaconic acid, or the like is used. Preferably, the urethane component and the acrylic component are chemically bonded. For example, (meth)acrylic acid-2-hydroxyethyl ester, (meth)acrylic acid are used in the acrylic component by using -Acrylic polyols such as 2-hydroxypropyl, 3-hydroxypropyl (meth)acrylate, and 4-hydroxybutyl acrylate, etc., can obtain amines that chemically bond the urethane component and the acrylic component Carbamate/acrylic composite resin (C).

As a urethane/acrylic composite resin (C), a commercial item can also be used. For example, WEM-031U, 200U, 202U, 321, 3000 and 290A; WAN-6000 and ACRIT 8UA-140 (the above, manufactured by Taisei Fine Chemical Co., Ltd.), etc. are mentioned.

In the case where the web printing ink contains the urethane/acrylic composite resin (C), the solid content weight of the aqueous urethane resin (A) and the urethane/acrylic composite resin (C) is better 85/15 or more, more preferably 90/10 or more, and more preferably 99/1 or less, more specifically, 85/15 to 99/1, more preferably 90/10 to 99/1 .

4. Colorants

As the colorant, known dyes or pigments can be used, preferably pigments, and are not particularly limited. The colors are white, cyan (C), magenta (M), yellow (Y), black (K), orange, purple and green, etc., and are not particularly limited. It is called the coloring agent described in CI). If necessary, colorants of different colors can also be used in any combination.

As the colorant, it is preferable to use one of a white colorant, a cyan colorant, a magenta colorant, a yellow colorant, and a black colorant.

The content of the colorant in the rotary printing ink is not particularly limited, and in the case of color inks, it is preferably 10% by weight or more, more preferably 15% by weight or more, and In addition, it is preferably 30% by weight or less, more preferably 25% by weight or less. In the case of white ink, it is preferably 25% by weight or more, more preferably 30% by weight or more, and preferably 50% by weight or less, more preferably 45% by weight or less. More specifically, in the case of color ink, it is preferably 10% by weight to 30% by weight, and more preferably 15% by weight to 25% by weight. In the case of white ink, it is preferably 25% by weight to 50% by weight, more preferably 30% by weight to 45% by weight.

5. Hydrocarbon wax

The melting point of the hydrocarbon-based wax is preferably from 90°C to 140°C, more preferably from 100°C to 140°C, from the viewpoints of friction resistance, blocking resistance, and the like. In addition, the average particle diameter of the hydrocarbon-based wax is preferably 0.5 μm to 10 μm from the viewpoints of blocking resistance, surface gloss, and the like. In the selection of the average particle diameter of the hydrocarbon-based wax, it is preferable to select it appropriately in relation to the thickness of the coating film. When the particle size is too small to be smaller than the thickness of the coating film, wax is buried in the coating film, and the blocking resistance tends to be poor despite having gloss. On the other hand, when the particle diameter is excessively larger than the thickness of the coating film, although the blocking resistance is improved, the tendency for the gloss to decrease is observed. Moreover, as for the hydrocarbon-based wax, when the penetration method hardness according to JIS K2235:1991 is 10 or less, the blocking resistance is improved, which is preferable.

The melting point of the hydrocarbon-based wax can be measured at a temperature increase rate of 10° C./min using, for example, a differential scanning calorimeter “DSC6200” (manufactured by Seiko Instruments).

The average particle size of the hydrocarbon-based wax can be measured by, for example, a laser diffraction/scattering particle size distribution analyzer "LA-920 type" (manufactured by Horiba, Ltd.).

As the hydrocarbon-based wax, for example, polyethylene wax, polypropylene wax, paraffin wax, A Fischer tropsch wax, a microcrystalline wax, or the like can also be used in combination of a plurality of them. As a commercial item, "WF640", "W300", and "W310" (all are trade names) manufactured by Mitsui Chemicals Co., Ltd. can be preferably used.

The content of the hydrocarbon-based wax in the web printing ink is not particularly limited, and the content of the hydrocarbon-based wax is guaranteed to be combined with the water-based urethane resin (A) and the water-based urethane urea resin (B) and urethane arbitrarily prepared. From the viewpoint of further improving the blocking resistance due to the miscibility of the ester/acrylic composite resin (C), it is preferably 0.5% by weight or more, more preferably 1% by weight or more, based on the total weight of the web printing ink, and further, It is preferably 7 wt % or less, more preferably 4 wt % or less, more specifically, 0.5 wt % to 7 wt %, more preferably 1 wt % to 4 wt %.

6. Water

Water is preferably 40% by weight to 70% by weight in the web printing ink. Further, in the color ink, it is preferably 40% by weight to 60% by weight, and in the white ink, it is preferably 50% by weight to 70% by weight.

7. Hydrazine compounds

In one embodiment, the web printing ink preferably contains a hydrazine compound. The hydrazide compound in the water-based urethane resin (A) or the water-based urethane urea resin (B) in the ink further improves the cohesive force, so the ink film becomes firm, which can improve the lamination strength and adhesion resistance. Connectivity etc. The content of the hydrazine compound is preferably 0.1 wt % or more, and preferably 0.8 wt % or less, more specifically, 0.1 to 0.8 wt % based on the total weight of the rotary printing ink. The hydrazide compound is not particularly limited, and preferred compounds include malonate dihydrazide and succinate dihydrazide. Hydrazine, glutaric acid dihydrazine, adipic acid dihydrazine, sebacic acid dihydrazine, etc. Among them, adipic acid dihydrazine is preferable.

8. Other ingredients

In addition, the web printing ink may contain known additives such as a defoamer, a tackifier, a leveling agent, a pigment dispersant, and an ultraviolet absorber as needed. In addition, organic solvents such as alcohol-based, ketone-based, and ester-based solvents may be included, and alcohol-based solvents are preferred from the viewpoint of environmental correspondence and the durability of the printing plate (flexographic printing). Specifically, n-propanol and isopropanol are preferred. When an organic solvent is contained, its content is preferably 20% by weight or less in the ink, more preferably 10% by weight or less.

In addition, resins other than the water-based urethane resin (A), the water-based urethane urea resin (B), and the urethane/acrylic composite resin (C) may also be included as a binder for the ink Element. Examples of resins that can be optionally included include conventional aqueous urethane resins other than the aforementioned aqueous urethane resin (A), polyester resins, acrylic resins, styrene-acrylic resins, styrene- Water-based resins such as maleic anhydride resins, rosin-modified maleic acid resins, cellulose-based resins, and chlorinated polyolefins may be used in combination.

The manufacturing method of a web printing ink is not specifically limited, For example, it can manufacture suitably by mixing and preparing a component using a ball mill, an attritor, a sand mill, or the like.

<Use of ink>

One embodiment of the present invention relates to the use of the rotary printing ink for rotary printing. That is, the use of an ink (rotary printing ink) for rotary printing, the ink (rotary printing ink) containing aqueous urethane Ester resin (A), colorant, hydrocarbon-based wax, and water. The details of the ink (rotary printing ink) used for this purpose are as described above.

<Use of web printing ink>

An embodiment of the present invention relates to the use of the web printing ink. That is, the use of a rotary printing ink for gravure printing, the rotary printing ink comprising an aqueous urethane resin (A1), an aqueous urethane resin (A2) and a white colorant and used for gravure printing print. In this case, as described above, the solid content weight ratio of the aqueous urethane resin (A1) and the aqueous urethane resin (A2) in the web printing ink is preferably 30/70 to 50/50. In addition, as described above, the web printing ink preferably includes a water-based urethane resin (A1) and a colorant of at least one color selected from the group consisting of cyan, magenta, yellow, and black. In addition, the details of the web printing ink used for gravure printing are as described above.

In addition, another embodiment is the use of a rotary printing ink for flexographic printing, the rotary printing ink further comprising an aqueous urethane urea resin (B) and used for the flexographic printing. Details of web printing inks for flexographic printing applications are as described above.

Another embodiment relates to the use of the web printing ink for forming the printing layer of a plastic film web printing product (described later) having a printing layer on the surface of the plastic film. Likewise, another embodiment relates to the use of the web printing ink for a laminate (described later) comprising a web of plastic film, and for printing on the surface of a plastic film forming web of a web of plastic film Floor.

<Gravure Rotary Printing Ink Set>

The rotogravure printing ink set of one embodiment includes rotogravure white ink and one or more rotogravure color inks.

As described above, the gravure rotary printing white ink preferably contains the aqueous urethane resin (A1), the aqueous urethane resin (A2), a white colorant, a hydrocarbon-based wax, and water.

As described above, the color ink for gravure rotary printing preferably contains the aqueous urethane resin (A1), a colorant, a hydrocarbon-based wax, and water. The ink set may also contain multiple color inks of different colors (ie, containing different color colorants). The color colorant preferably includes a colorant of at least one color selected from the group consisting of cyan, magenta, yellow, and black, or a colorant of one of these colors, and may also include a colorant of other colors Ink set of color inks.

<Flexographic Web Printing Ink Set>

The flexographic web printing ink set of one embodiment includes flexographic web printing white ink and one or more flexographic web printing color inks.

As described above, the flexographic web printing white ink preferably contains the aqueous urethane resin (A2), the aqueous urethane urea resin (B), a colorant, a hydrocarbon-based wax, and water. Furthermore, it is also preferable to contain a urethane/acrylic composite resin (C).

As described above, the color ink for flexographic rotary printing preferably contains the aqueous urethane resin (A2), the aqueous urethane urea resin (B), a colorant, a hydrocarbon-based wax, and water. Furthermore, it is also preferable to contain a urethane/acrylic composite resin (C). Ink sets may also contain different colors (ie, contain different colorants) Multiple color inks. The color colorant preferably includes a colorant of at least one color selected from the group consisting of cyan, magenta, yellow, and black, or a colorant of one of these colors, and may also include a colorant of other colors Ink set of color inks.

<Use of web printing ink set>

An embodiment of the present invention relates to the use of the above-mentioned web printing ink set. That is, a use of the rotogravure ink set for gravure printing, the rotogravure ink set comprising rotogravure white ink and one or more rotogravure color inks.

Another embodiment is the use of the flexographic web printing ink set for flexographic printing, the flexographic web printing ink set comprising flexographic web printing white ink and more than one flexographic web printing color ink.

Another embodiment relates to the use of the rotary printing ink set for forming the printing layer of a plastic film web printing product (described later) having a printing layer on the surface of the plastic film. Likewise, another embodiment relates to the use of the web-printing ink set for laminations (described later) comprising web-printed plastic films, and for forming the surface of the plastic film for web-printed plastic films printing layer. Here, the web printing ink set includes a gravure web printing color ink set and a flexographic web printing ink set.

<Plastic film web printing>

In one embodiment, the plastic film rotary printing has a printing layer on the surface of the plastic film, and the printing layer uses the various rotary printing inks or the gravure rotary printing It is formed by brushing ink sets or flexographic web printing ink sets. The web printing ink can also be used in either gravure printing or flexographic printing according to the target print.

The type, thickness, and the like of the plastic film are not particularly limited, and examples of the type of the film include polyester-based films, nylon films, polyolefin films, and vapor-deposited products of these metal oxides. In the case of a polyolefin film, if a corona discharge-treated polyolefin film has a functional group such as a hydroxyl group or a carbonyl group, a favorable printed matter can be obtained. As the plastic film, a uniaxially or biaxially stretched film is preferable. Prints are often processed as rolls, which are subsequently cut to specific dimensions through lamination steps, slitting steps, etc., if desired.

<Manufacturing method of plastic film web printing>

The manufacturing method of the plastic film web printing in one embodiment includes using the web printing ink, the gravure web printing ink set or the flexo web printing ink set to perform web printing on the surface of the reeled plastic film. After printing, steps such as lamination, slitting (cutting unnecessary parts of the width portion), bag making (cutting and heat sealing to make bags) can be performed.

High-speed printing with excellent productivity is achieved by rotary printing the printing ink onto the reeled plastic film.

Gravure rotary printing is generally a printing method in which a gravure plate having grooves (recesses) for expressing patterns and/or characters, etc. is provided on the peripheral surface of a cylindrical drum, the grooves are filled with printing ink, and a metal scraper is used to fill the grooves with printing ink. Scrape off the ink attached to the outside of the groove, and press the printed body (plastic film) to pass between the gravure and the impression cylinder, so that the printing ink filled in the groove is transferred to the printed body, so that the Reproduction of drawings and/or characters, etc. on the printed matter.

In flexographic rotary printing, ink is supplied from a container storing printing ink to an anilox roller having an uneven surface, directly or via an ink supply pump, etc., and the ink supplied to the anilox roller is contacted with the layout The contact of the convex portion is transferred to the layout, and then finally transferred to the plastic film by the contact of the layout and the plastic film, thereby forming patterns and/or characters.

In addition, in this specification, the so-called rotary printing refers to gravure rotary printing and flexographic rotary printing, and does not include inkjet printing and screen printing methods as other printing methods.

The roll-up plastic film refers to a roll-shaped plastic film having a predetermined width, and is a film for web printing, which is different from the continuous-page paper that has been cut off one by one in advance. The width of the film can be appropriately selected on the basis of the plate width of the rotary printing press to be used and the width of the image (design) portion of the gravure plate.

In the case where multiple colors of web printing inks are used and the colors are superimposed, the printing order of these is not particularly limited.

In the gravure rotary printing and flexographic rotary printing methods, in the case of back printing, usually the color ink is first printed on the reeled plastic film, and then the white ink is printed. When there are color inks of multiple colors, for example, printing can be performed in the order of black, cyan, magenta, and yellow, but it is not particularly limited. Furthermore, in a large-scale printing press, in addition to the above-described basic colors, special colors and the like may be used. That is, a large-scale printing press has a plurality of printing units corresponding to 5 to 10 colors, and one printing unit includes ink of one color, and can perform overlapping printing of 5 to 10 colors at a time. Laminated laminates can be obtained by: An adhesion-promoting coating agent, an adhesive, etc. are apply|coated to the printing surface of the rotary printed matter obtained by the said method, and it is bonded to a film etc. after drying as needed.

In surface printing, white ink is usually printed first, followed by color ink, as needed. In the case where there are color inks of multiple colors, for example, printing can be performed in the order of yellow, magenta, cyan, and black, but it is not particularly limited. In the case of the surface printing structure, the wear resistance, water resistance, etc. can be improved by coating an overcoating agent on the printing surface of the rotary printed matter as necessary.

When the base material is a white type, that is, for example, in the case of a paper base material and a plastic film kneaded with a white type pigment, printing with only the color ink can be performed as necessary.

The laminated laminate of one embodiment includes the plastic film web printing. That is, it can be preferably obtained by laminating the plastic film web printing.

As the lamination processing method, the following methods can be mentioned: 1) Extrusion lamination method, in which a tackifying coating agent is applied on the printing surface of the obtained printed matter as necessary, followed by melting a resin and a plastic film in this order. Lamination; or 2) dry lamination method, after applying an adhesive on the printing surface of the obtained printed matter, drying if necessary, and laminating a plastic film. As the molten resin, low-density polyethylene, polypropylene, ethylene-vinyl acetate copolymer, etc. can be used, and as the adhesive, imine-based, isocyanate-based, polybutadiene-based, titanate-based, and the like can be used.

The laminated laminate can be preferably used as a packaging material, and in addition to the usual packaging materials, it can also be used particularly preferably as a packaging material for food.

[Example]

Next, the examples of the present invention will be described, but the present invention is not limited to these examples, and it goes without saying that many embodiments other than these based on the gist of the invention are included. In addition, unless otherwise specified, "parts" and "%" are based on weight. In addition, the web printing ink can also be abbreviated as "ink".

<Synthesis of aqueous urethane resin (A)>

(Synthesis Example 1)

74.3 parts of polytetramethylene glycol with a number average molecular weight of 2,000 and 3 parts of polytetramethylene glycol with a number average molecular weight of 2,000 were put into a four-neck 2,000-ml flask equipped with a reflux cooling tube, a dropping funnel, a gas introduction tube, a stirring device, and a thermometer. of polyethylene glycol, 13 parts of dimethylolbutyric acid, 8 parts of bis(2-hydroxypropyl)aniline and 1.7 parts of 1,4-cyclohexanedimethanol were replaced with dry nitrogen, and the temperature was increased. to 100°C. Under stirring, 41.3 parts of isophorone diisocyanate was added dropwise over 20 minutes, and the temperature was gradually raised to 140° C. (NCO/OH=0.98). Furthermore, the reaction was performed for 30 minutes to obtain a urethane resin. Then, 750 parts of distilled water containing 8.9 parts of 28% ammonia water was added while cooling, to obtain an aqueous urethane resin (A1-1) (weight average molecular weight about 40,000).

The weight average molecular weight is obtained by measuring the molecular weight distribution using a gel permeation chromatography (GPC) apparatus (HLC-8220, manufactured by Tosoh Corporation), and using polystyrene as a reference material in terms of molecular weight. The measurement conditions are shown below.

Column: The following columns were connected in series and used.

Guard column HXL-H manufactured by Tosoh Corporation

TSKgel G5000HXL manufactured by Tosoh Corporation

TSKgelG4000HXL manufactured by Tosoh Corporation

TSKgelG3000HXL manufactured by Tosoh Corporation

TSKgelG2000HXL manufactured by Tosoh Corporation

Detector: RI (differential refractometer)

Measurement conditions: column temperature 40°C

Eluent: tetrahydrofuran

Flow rate: 1.0mL/min

(Synthesis Example 2 to Synthesis Example 9)

Water-based urethane resin (A1-2) to water-based urethane resin (A1-9) were synthesized using the raw material compounds shown in Table 1 in the same manner as in Synthesis Example 1. In addition, the neutralization with 28% ammonia water was performed so that it might become an equimolar amount with the carboxyl group derived from dimethylol butyric acid similarly to Synthesis Example 1.

The abbreviations of each raw material compound in Table 1 represent the following compounds, respectively.

MPD/AA: 3-methyl-1,5-pentanediol/adipic acid (polyester polyol)

PTG: Polytetramethylene glycol (polyether polyol)

PEG: polyethylene glycol (polyether polyol)

DMBA: Dimethylolbutyric acid

Bis-HPA: Bis(2-hydroxypropylaniline)

CHDM: 1,4-cyclohexanedimethanol

TMP: Trimethylolpropane

IPDI: isophorone diisocyanate

[Table 1]

(Synthesis Example 10 to Synthesis Example 14)

Water-based urethane resin (A2-1) to water-based urethane resin (A2-5) were synthesized using the raw material compounds shown in Table 2 in the same manner as in Synthesis Example 1.

[Table 2]

(Comparative Synthesis Example 1 to Comparative Synthesis Example 6)

Using the raw material compounds shown in Table 3 in the same manner as in Synthesis Example 1, comparative aqueous urethane resin (PU1) to comparative aqueous urethane resin (PU6) were synthesized.

[table 3]

<Synthesis of aqueous urethane urea resin (B)>

(Synthesis Example 15)

77.6 parts of poly(neopentyl adipate) glycol (NPG) having a number-average molecular weight of 2,000 was mixed in a reactor equipped with a reflux cooling tube, a dropping funnel, a gas introduction tube, a stirring device, and a thermometer while introducing nitrogen gas. /AA), 8 parts of polyethylene glycol (PEG) with a number average molecular weight of 2000, 14.4 parts of 2,2-dimethylolbutyric acid (DMBA) and 40.6 parts of methyl ethyl ketone (MEK) and added While stirring, the temperature was raised. At the boiling temperature, 62.2 parts of isophorone diisocyanate (IPDI) was added dropwise over 1 hour, and further, a boiling point reaction was performed for 4 hours to prepare a terminal isocyanate prepolymer, and after cooling to 30° C., 100 parts of isophorone diisocyanate was added. parts of isopropanol to obtain a solvent solution of the terminal isocyanate prepolymer. In what mixed 25.7 parts of isophorone diamine (IPDA) and 400 parts of isopropanol, the total amount of the obtained terminal isocyanate prepolymer solution was slowly added at room temperature, and the reaction was carried out at 40°C. A solvent-type polyurethane resin solution was obtained in 2 hours. Next, 5.9 parts of 28% ammonia water and 485.8 parts of ion-exchanged water were gradually added to the solvent-type polyurethane resin solution for neutralization, and water-solubilization was performed thereby, and further, azeotropically The methyl ethyl ketone and isopropanol were distilled off, and then water was added to adjust the viscosity to obtain an aqueous urethane urea resin (B -1).

(Synthesis Example 16)

An aqueous urethane urea resin (B-2) was synthesized using the raw material compounds shown in Table 4 in the same manner as in Synthesis Example 15. Furthermore, using 28% ammonia water for neutralization and combination In the same manner as in Example 11, the amount of the carboxyl group derived from DMBA was equimolar. In Table 4, AEA is 2-aminoethylethanolamine.

<Production of Inks of Examples and Comparative Examples>

Each raw material shown in Table 5 was stirred for 10 minutes with an Eiger Mill (manufactured by EIGER) to produce inks of Examples. In addition, the ink of the comparative example was produced similarly using the raw material shown in Table 6. Table 7 shows the details of the hydrocarbon-based wax used. Examples 1 to 8 in Table 5-1 are examples of color inks that are particularly preferred for gravure printing, and Examples 9 to 13 are examples of white inks that are particularly preferred for gravure printing. Table 5-2 of the actual Examples 14 to 23 are examples of color inks that are particularly preferable for flexographic printing applications, and Examples 24 to 26 are examples of white inks that are particularly preferable for flexographic printing applications. Examples 27 to 29 in Table 5-3 are examples of ink sets that are particularly suitable for gravure printing, and Examples 30 to 32 are examples of ink sets that are particularly suitable for flexographic printing. Example, Example 33 and Example 34 are examples of color inks that are particularly suitable for gravure printing, Example 35 is an example of white ink that is particularly suitable for gravure printing, and Example 36 is flexographic printing. An example of a white ink that is particularly good for its purpose. The urethane/acrylic composite resin (C) used was "WEM-202U" manufactured by Taisei Fine Chemical Co., Ltd.

[Table 5-1]

[Table 5-2]

[Table 5-3]

[Table 6]

<Evaluation method and evaluation criteria>

Printing in Examples and Comparative Examples was performed as follows.

Gravure Rotary Printing: Using a small printing press of Iwase Printing Machinery Co., Ltd., the plastic film is printed at a speed of 50m/min, and dried at 60°C to 70°C to obtain a printed matter. The plate uses an etching 200-line plate with a depth of 20 μm for the entire plate.

Flexographic web printing: Using a center cylinder type 6-color flexographic printing machine "SOLOFLEX" manufactured by Windmoller & Holscher, the plastic film was processed at a speed of 100 m/min. Printing, and drying at 60°C to 70°C to obtain a printed matter. As an anilox roll, 350 lines/cm was used, and as a printing plate cylinder, Du Pont's "Cyrel" was attached with a double-sided tape ("DF7382T" manufactured by Toyo Ink Co., Ltd., thickness 0.50 mm). DPU" (thickness 1.14mm) is used by those who make a full-face plate.

(1) Ink stability

After the ink was kept at a constant temperature of 40°C for 3 months, the viscosity over time was measured using Zahn cup No. 4 (25°C), and the difference from the finished (initial) viscosity was evaluated. The evaluation criteria are shown below. The practical level is C or higher.

A: The difference between the finished viscosity and the elapsed viscosity is less than 2 seconds

B: The difference between the finished viscosity and the elapsed viscosity is 2 seconds or more and less than 4 seconds

C: The difference between the finished viscosity and the elapsed viscosity is 4 seconds or more and less than 6 seconds

D: The difference between the finished viscosity and the elapsed viscosity is 6 seconds or more and less than 8 seconds

E: The difference between the finished viscosity and the elapsed viscosity is 8 seconds or more

(2) Color rendering

The ink was developed on a PET film (polyethylene terephthalate film, E-5102 manufactured by Toyobo Co., Ltd., 12 μm) using a Mayer bar, and the transparency, concentration and gloss. The higher the transparency, the higher the density, and the higher the gloss, it was judged that the color rendering property was better. The evaluation criteria are shown below. The practical level is C or higher.

A: Transparency is high, density is high, and gloss is high.

B: Transparency, density, and high gloss.

C: Translucency and density are slightly inferior, and there is moderate gloss.

D: Transparency, poor density, and insufficient gloss.

E: No translucency, no density, and no gloss.

(3) Resolubility

The ink was coated on a Ballard plate, and after air-drying, 25 ml of diluent solvent (water/n-propanol mixed solvent, weight ratio 70/30) was hung, and the dissolution of the printing ink film was visually determined. The practical level is D or higher.

A: All dissolved.

B: Slight dissolution residue was confirmed.

C: Dissolved residues in an area of less than 10% were confirmed.

D: Dissolved residues in an area of 10% or more and less than 30% were confirmed.

E: Dissolved residues in an area of 30% or more were confirmed.

(4) Substrate adhesion

A 10mm wide adhesive tape manufactured by Nichiban Co., Ltd. was attached to the printed matter printed with ink on OPP film (extended polypropylene film, P-2161 manufactured by Toyobo Co., Ltd., 30 μm), and A peel test was performed. The transfer state (acquired state) of the ink film to the adhesive tape (scotch tape manufactured by Nichiban) was visually evaluated according to the following criteria. The evaluation criteria are shown below. The practical level is C or higher.

A: The ink was not transferred to the adhesive tape at all.

B: Transfer of ink of less than 5% was confirmed on the adhesive tape.

C: The transfer of ink of 5% or more and less than 10% was confirmed on the adhesive tape.

D: Transfer of 10% or more and less than 50% of ink was confirmed on the adhesive tape.

E: Transfer of 50% or more of ink was confirmed on the adhesive tape.

(5) Blocking resistance

The printed matter obtained by printing ink on the OPP film (the P-2161) was sampled at 4 cm×4 cm, and the printed surface of the sample was combined with the non-corona treated surface of the unprinted film of the same size to be heated at 40°C. Under pressure of 10 kgf/cm ² for 12 hours, the ink transfer and resistance feeling when the sample was peeled off were observed. The evaluation criteria are shown below. The practical level is C or higher.

A: The transfer of the ink from the printed matter was not confirmed at all, and there was no resistance feeling at the time of peeling.

B: The transfer of the ink from the printed matter was not confirmed at all, but there was a sense of resistance at the time of peeling.

C: The transfer of the ink from the printed matter was confirmed, and the area was less than 10%.

D: The transfer of ink from the printed matter was confirmed in an area of 10% or more and less than 50%.

E: The transfer of the ink from the printed matter was confirmed in an area of 50% or more.

(6) Water resistance

The surface of the printed matter obtained by printing ink on the OPP film (the P-2161 described above) was lightly wiped 10 times with a water-containing absorbent cotton, and was visually evaluated according to the following criteria. The evaluation criteria are shown below. The practical level is C or higher.

A: Even after wiping 10 times, peeling and dissolution of the ink surface were not confirmed.

B: After wiping 10 times, the ink surface peeled off and dissolved in about half of the area.

C: After wiping 10 times, most of the ink surface was peeled off and dissolved.

D: When wiping 5 times, most of the ink surface was peeled off and dissolved.

E: When wiping twice, most of the ink surface was peeled off and dissolved.

(7) Lamination strength

On the printed matter obtained by printing the ink on the OPP film (the P-2161 described above), an imine-based tackifying coating agent (EL-420 manufactured by Toyo Morton Co., Ltd.) was applied, and an extrusion coating was used. Out of the laminator, the polyethylene melted at 315°C is separated from the CPP The films (unstretched polypropylene film with a thickness of 30 μm; sealant film) were bonded to obtain a laminated product (extrusion lamination method). The processed product was cut with a width of 15 mm, and the peel strength at the time of interlayer peeling between the ink surface and the OPP film surface was measured using a 201 universal tensile tester manufactured by INTESCO. The evaluation criteria are shown below. The practical level is C or higher.

A: The peel strength is 0.9N/15mm or more

B: The peel strength is 0.7N/15mm or more and less than 0.9N/15mm

C: The peel strength is 0.5N/15mm or more and less than 0.7N/15mm

D: The peel strength is 0.3N/15mm or more and less than 0.5N/15mm

E: The peel strength is less than 0.3N/15mm

(8) Plate whitening (evaluation for gravure ink)

With respect to 100 parts of ink, a mixed solvent of water/isopropyl alcohol (mixing ratio of 1:1) was added, and the viscosity of Zahn cup #3 manufactured by Clutch (stock) was adjusted to 16 seconds. And using a gravure rotary printing press with a gravure plate with a plate depth of 25 μm and a doctor blade with a blade edge thickness of 65 μ (trade name "New Doctor Hyblade", manufactured by Fuji Shoko Co., Ltd.), the printing process was carried out at a rate of 100 m/m. After idling at a drum rotation speed of min for 60 minutes, the corona-discharge-treated surface of the PET film (the E-5102) was printed at a printing speed of 100 m/min, and dried with hot air at 60° C. to obtain a printed matter.

The amount of ink adhering to the blank portion (non-image portion) of the obtained printed film was visually evaluated according to the following criteria. The evaluation criteria are shown below. The practical level is C or higher.

A: In the non-image area, the transfer of ink was not confirmed at all.

B: In a small area (less than 5%) of the non-image portion, ink transfer was slightly observed.

C: In the middle area (5% to less than 10%) of the non-image portion, ink transfer was confirmed.

D: In a large area (10% or more) of the non-image portion, the transfer of ink was confirmed.

E: Ink transfer was confirmed on the entire surface of the non-image portion.

(9) Washability (evaluation of flexographic ink)

The ink was developed on an OPP film (the P-2161) and dried at room temperature for 10 minutes. Then, water, n-propanol, and Magiclean (a special solvent for plate washing, manufactured by Kao Co., Ltd.) were dropped on the coating film, respectively, and the solubility of the coating film was investigated, and it was set as the plate washing property. Simple evaluation. The evaluation criteria are shown below. The practical level is C or higher.

A: Dissolves only in water.

B: Dissolution occurs only in n-propanol.

C: Dissolved in Wanjieling.

D: Even in Wanjieling, it does not dissolve.

The obtained results are shown in Table 8 (Example) and Table 9 (Comparative Example).

[Table 8-1]

[Table 8-2]

[Table 8-3]

As shown in Table 8 (Table 8-1 to Table 8-3), in the Examples, inks with blocking resistance, water resistance and lamination strength above practical levels were obtained, which were confirmed to be suitable for use in plastic films. Ink on web printing. On the other hand, as shown in Table 9 (Table 9-1 to Table 9-2), with respect to the ink of the comparative example, any one or more of blocking resistance, water resistance, and lamination strength did not satisfy the practical level.

Claims (14)

A rotary printing ink containing water-based urethane resin (A), a colorant, a hydrocarbon-based wax and water, wherein the acid value of the water-based urethane resin (A) in the rotary printing ink is 25 mgKOH/g ~45 mgKOH/g, and includes structural units of polyether-based and/or polyester-based high-molecular-weight diols, structural units represented by the following general formula (1) and general formula (2), and three or more in the same molecule The structural unit of the compound of the functional group that can react with the isocyanate group, the structural unit of the general formula (1) contains 5% by weight to 10% by weight in the resin solid content, and the structural unit of the general formula (2) is in the resin solid content. Contains 0.5% by weight to 5% by weight, the melting point of the hydrocarbon wax is 90 ° C ~ 140 ° C, and the average particle diameter is 0.5 μm ~ 10 μm; general formula (1) >N-Ph In general formula (1), Ph represents the Substituted or unsubstituted phenyl group, general formula (2) -R ¹ -AR ² - In general formula (2), R ¹ and R ² represent substituted or unsubstituted aliphatic hydrocarbon groups, which may be the same or different , A represents an alicyclic hydrocarbon group. The web printing ink according to claim 1, wherein the aqueous urethane resin (A) contains at least a One, the water-based urethane resin (A1) has 3% to 7% by weight of polyethylene glycol units in the solid content of the water-based urethane resin (A1), and the water-based urethane resin (A1) The acid ester resin (A2) has a polyethylene glycol unit of 20% by weight to 30% by weight in the solid content of the aqueous urethane resin (A2). The web printing ink according to claim 2, which comprises an aqueous urethane resin (A1), an aqueous urethane resin (A2) and a white colorant, and is used for gravure printing. The rotary printing ink according to claim 2 or claim 3, wherein, in the case of including both the water-based urethane resin (A1) and the water-based urethane resin (A2), The solid content weight ratio of the aqueous urethane resin (A1) and the aqueous urethane resin (A2) is 30/70 to 50/50. The web printing ink according to item 2 of the claimed scope, comprising a water-based urethane resin (A1) and a colorant of at least one color selected from the group consisting of cyan, magenta, yellow and black , and for gravure printing. The web printing ink according to claim 1 or claim 2, further comprising an aqueous urethane urea resin (B) comprising a branched urethane urea resin (B) Polyester polyol units. The web printing ink according to claim 6, wherein the solids of the aqueous urethane resin (A) and the aqueous urethane urea resin (B) are The weight ratio of ingredients is 25/75~45/55. The web printing ink according to claim 6, wherein the aqueous urethane resin (A) contains an aqueous urethane resin (A2), and the aqueous urethane resin (A2) The aqueous urethane resin (A2) has a polyethylene glycol unit of 20% by weight to 30% by weight in the solid content. The web printing ink according to claim 6, further comprising a urethane/acrylic composite resin (C). The web printing ink described in claim 6, which is used for flexographic printing. A gravure rotary printing ink set, comprising the rotary printing ink described in item 3 of the patent application scope and one or more kinds of rotary printing inks described in the fifth item of the patent application scope. A flexographic rotary printing ink set, comprising two or more kinds of rotary printing inks as described in item 10 of the patent application scope, the flexographic rotary printing ink set is a combination of the following flexographic rotary printing inks: including white coloring flexographic rotary printing inks; and one or more flexographic rotary printing inks comprising colorants of at least one color selected from the group consisting of cyan, magenta, yellow, and black. A plastic film rotary printing, which has a printing layer on the surface of the plastic film. The gravure rotary printing ink set described in item 1 or the flexographic rotary printing ink set described in claim 12 any one of the groups. A laminated laminate, comprising the plastic film web printing as described in item 13 of the patent application scope.